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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  Digital Audio (PCM) abstract layer
  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
  */
 
 #include <linux/compat.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/file.h>
 #include <linux/slab.h>
 #include <linux/sched/signal.h>
 #include <linux/time.h>
 #include <linux/pm_qos.h>
 #include <linux/io.h>
 #include <linux/dma-mapping.h>
 #include <linux/vmalloc.h>
 #include <sound/core.h>
 #include <sound/control.h>
 #include <sound/info.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/timer.h>
 #include <sound/minors.h>
 #include <linux/uio.h>
 #include <linux/delay.h>
 
 #include "pcm_local.h"
 
 #ifdef CONFIG_SND_DEBUG
 #define CREATE_TRACE_POINTS
 #include "pcm_param_trace.h"
 #else
 #define trace_hw_mask_param_enabled()       0
 #define trace_hw_interval_param_enabled()   0
 #define trace_hw_mask_param(substream, type, index, prev, curr)
 #define trace_hw_interval_param(substream, type, index, prev, curr)
 #endif
 
 /*
  *  Compatibility
  */
 
 struct snd_pcm_hw_params_old {
     unsigned int flags;
     unsigned int masks[SNDRV_PCM_HW_PARAM_SUBFORMAT -
                SNDRV_PCM_HW_PARAM_ACCESS + 1];
     struct snd_interval intervals[SNDRV_PCM_HW_PARAM_TICK_TIME -
                     SNDRV_PCM_HW_PARAM_SAMPLE_BITS + 1];
     unsigned int rmask;
     unsigned int cmask;
     unsigned int info;
     unsigned int msbits;
     unsigned int rate_num;
     unsigned int rate_den;
     snd_pcm_uframes_t fifo_size;
     unsigned char reserved[64];
 };
 
 #ifdef CONFIG_SND_SUPPORT_OLD_API
 #define SNDRV_PCM_IOCTL_HW_REFINE_OLD _IOWR('A', 0x10, struct snd_pcm_hw_params_old)
 #define SNDRV_PCM_IOCTL_HW_PARAMS_OLD _IOWR('A', 0x11, struct snd_pcm_hw_params_old)
 
 static int snd_pcm_hw_refine_old_user(struct snd_pcm_substream *substream,
                       struct snd_pcm_hw_params_old __user * _oparams);
 static int snd_pcm_hw_params_old_user(struct snd_pcm_substream *substream,
                       struct snd_pcm_hw_params_old __user * _oparams);
 #endif
 static int snd_pcm_open(struct file *file, struct snd_pcm *pcm, int stream);
 
 /*
  *
  */
 
 static DECLARE_RWSEM(snd_pcm_link_rwsem);
 
 void snd_pcm_group_init(struct snd_pcm_group *group)
 {
     spin_lock_init(&group->lock);
     mutex_init(&group->mutex);
     INIT_LIST_HEAD(&group->substreams);
     refcount_set(&group->refs, 1);
 }
 
 /* define group lock helpers */
 #define DEFINE_PCM_GROUP_LOCK(action, mutex_action) \
 static void snd_pcm_group_ ## action(struct snd_pcm_group *group, bool nonatomic) \
 { \
     if (nonatomic) \
         mutex_ ## mutex_action(&group->mutex); \
     else \
         spin_ ## action(&group->lock); \
 }
 
 DEFINE_PCM_GROUP_LOCK(lock, lock);
 DEFINE_PCM_GROUP_LOCK(unlock, unlock);
 DEFINE_PCM_GROUP_LOCK(lock_irq, lock);
 DEFINE_PCM_GROUP_LOCK(unlock_irq, unlock);
 
 /**
  * snd_pcm_stream_lock - Lock the PCM stream
  * @substream: PCM substream
  *
  * This locks the PCM stream's spinlock or mutex depending on the nonatomic
  * flag of the given substream.  This also takes the global link rw lock
  * (or rw sem), too, for avoiding the race with linked streams.
  */
 void snd_pcm_stream_lock(struct snd_pcm_substream *substream)
 {
     snd_pcm_group_lock(&substream->self_group, substream->pcm->nonatomic);
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stream_lock);
 
 /**
  * snd_pcm_stream_unlock - Unlock the PCM stream
  * @substream: PCM substream
  *
  * This unlocks the PCM stream that has been locked via snd_pcm_stream_lock().
  */
 void snd_pcm_stream_unlock(struct snd_pcm_substream *substream)
 {
     snd_pcm_group_unlock(&substream->self_group, substream->pcm->nonatomic);
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock);
 
 /**
  * snd_pcm_stream_lock_irq - Lock the PCM stream
  * @substream: PCM substream
  *
  * This locks the PCM stream like snd_pcm_stream_lock() and disables the local
  * IRQ (only when nonatomic is false).  In nonatomic case, this is identical
  * as snd_pcm_stream_lock().
  */
 void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream)
 {
     snd_pcm_group_lock_irq(&substream->self_group,
                    substream->pcm->nonatomic);
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stream_lock_irq);
 
 static void snd_pcm_stream_lock_nested(struct snd_pcm_substream *substream)
 {
     struct snd_pcm_group *group = &substream->self_group;
 
     if (substream->pcm->nonatomic)
         mutex_lock_nested(&group->mutex, SINGLE_DEPTH_NESTING);
     else
         spin_lock_nested(&group->lock, SINGLE_DEPTH_NESTING);
 }
 
 /**
  * snd_pcm_stream_unlock_irq - Unlock the PCM stream
  * @substream: PCM substream
  *
  * This is a counter-part of snd_pcm_stream_lock_irq().
  */
 void snd_pcm_stream_unlock_irq(struct snd_pcm_substream *substream)
 {
     snd_pcm_group_unlock_irq(&substream->self_group,
                  substream->pcm->nonatomic);
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irq);
 
 unsigned long _snd_pcm_stream_lock_irqsave(struct snd_pcm_substream *substream)
 {
     unsigned long flags = 0;
     if (substream->pcm->nonatomic)
         mutex_lock(&substream->self_group.mutex);
     else
         spin_lock_irqsave(&substream->self_group.lock, flags);
     return flags;
 }
 EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave);
 
 unsigned long _snd_pcm_stream_lock_irqsave_nested(struct snd_pcm_substream *substream)
 {
     unsigned long flags = 0;
     if (substream->pcm->nonatomic)
         mutex_lock_nested(&substream->self_group.mutex,
                   SINGLE_DEPTH_NESTING);
     else
         spin_lock_irqsave_nested(&substream->self_group.lock, flags,
                      SINGLE_DEPTH_NESTING);
     return flags;
 }
 EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave_nested);
 
 /**
  * snd_pcm_stream_unlock_irqrestore - Unlock the PCM stream
  * @substream: PCM substream
  * @flags: irq flags
  *
  * This is a counter-part of snd_pcm_stream_lock_irqsave().
  */
 void snd_pcm_stream_unlock_irqrestore(struct snd_pcm_substream *substream,
                       unsigned long flags)
 {
     if (substream->pcm->nonatomic)
         mutex_unlock(&substream->self_group.mutex);
     else
         spin_unlock_irqrestore(&substream->self_group.lock, flags);
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irqrestore);
 
 /* Run PCM ioctl ops */
 static int snd_pcm_ops_ioctl(struct snd_pcm_substream *substream,
                  unsigned cmd, void *arg)
 {
     if (substream->ops->ioctl)
         return substream->ops->ioctl(substream, cmd, arg);
     else
         return snd_pcm_lib_ioctl(substream, cmd, arg);
 }
 
 int snd_pcm_info(struct snd_pcm_substream *substream, struct snd_pcm_info *info)
 {
     struct snd_pcm *pcm = substream->pcm;
     struct snd_pcm_str *pstr = substream->pstr;
 
     memset(info, 0, sizeof(*info));
     info->card = pcm->card->number;
     info->device = pcm->device;
     info->stream = substream->stream;
     info->subdevice = substream->number;
     strscpy(info->id, pcm->id, sizeof(info->id));
     strscpy(info->name, pcm->name, sizeof(info->name));
     info->dev_class = pcm->dev_class;
     info->dev_subclass = pcm->dev_subclass;
     info->subdevices_count = pstr->substream_count;
     info->subdevices_avail = pstr->substream_count - pstr->substream_opened;
     strscpy(info->subname, substream->name, sizeof(info->subname));
 
     return 0;
 }
 
 int snd_pcm_info_user(struct snd_pcm_substream *substream,
               struct snd_pcm_info __user * _info)
 {
     struct snd_pcm_info *info;
     int err;
 
     info = kmalloc(sizeof(*info), GFP_KERNEL);
     if (! info)
         return -ENOMEM;
     err = snd_pcm_info(substream, info);
     if (err >= 0) {
         if (copy_to_user(_info, info, sizeof(*info)))
             err = -EFAULT;
     }
     kfree(info);
     return err;
 }
 
 /* macro for simplified cast */
 #define PARAM_MASK_BIT(b)   (1U << (__force int)(b))
 
 static bool hw_support_mmap(struct snd_pcm_substream *substream)
 {
     struct snd_dma_buffer *dmabuf;
 
     if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_MMAP))
         return false;
 
     if (substream->ops->mmap || substream->ops->page)
         return true;
 
     dmabuf = snd_pcm_get_dma_buf(substream);
     if (!dmabuf)
         dmabuf = &substream->dma_buffer;
     switch (dmabuf->dev.type) {
     case SNDRV_DMA_TYPE_UNKNOWN:
         /* we can't know the device, so just assume that the driver does
          * everything right
          */
         return true;
     case SNDRV_DMA_TYPE_CONTINUOUS:
     case SNDRV_DMA_TYPE_VMALLOC:
         return true;
     default:
         return dma_can_mmap(dmabuf->dev.dev);
     }
 }
 
 static int constrain_mask_params(struct snd_pcm_substream *substream,
                  struct snd_pcm_hw_params *params)
 {
     struct snd_pcm_hw_constraints *constrs =
                     &substream->runtime->hw_constraints;
     struct snd_mask *m;
     unsigned int k;
     struct snd_mask old_mask;
     int changed;
 
     for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++) {
         m = hw_param_mask(params, k);
         if (snd_mask_empty(m))
             return -EINVAL;
 
         /* This parameter is not requested to change by a caller. */
         if (!(params->rmask & PARAM_MASK_BIT(k)))
             continue;
 
         if (trace_hw_mask_param_enabled())
             old_mask = *m;
 
         changed = snd_mask_refine(m, constrs_mask(constrs, k));
         if (changed < 0)
             return changed;
         if (changed == 0)
             continue;
 
         /* Set corresponding flag so that the caller gets it. */
         trace_hw_mask_param(substream, k, 0, &old_mask, m);
         params->cmask |= PARAM_MASK_BIT(k);
     }
 
     return 0;
 }
 
 static int constrain_interval_params(struct snd_pcm_substream *substream,
                      struct snd_pcm_hw_params *params)
 {
     struct snd_pcm_hw_constraints *constrs =
                     &substream->runtime->hw_constraints;
     struct snd_interval *i;
     unsigned int k;
     struct snd_interval old_interval;
     int changed;
 
     for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++) {
         i = hw_param_interval(params, k);
         if (snd_interval_empty(i))
             return -EINVAL;
 
         /* This parameter is not requested to change by a caller. */
         if (!(params->rmask & PARAM_MASK_BIT(k)))
             continue;
 
         if (trace_hw_interval_param_enabled())
             old_interval = *i;
 
         changed = snd_interval_refine(i, constrs_interval(constrs, k));
         if (changed < 0)
             return changed;
         if (changed == 0)
             continue;
 
         /* Set corresponding flag so that the caller gets it. */
         trace_hw_interval_param(substream, k, 0, &old_interval, i);
         params->cmask |= PARAM_MASK_BIT(k);
     }
 
     return 0;
 }
 
 static int constrain_params_by_rules(struct snd_pcm_substream *substream,
                      struct snd_pcm_hw_params *params)
 {
     struct snd_pcm_hw_constraints *constrs =
                     &substream->runtime->hw_constraints;
     unsigned int k;
     unsigned int *rstamps;
     unsigned int vstamps[SNDRV_PCM_HW_PARAM_LAST_INTERVAL + 1];
     unsigned int stamp;
     struct snd_pcm_hw_rule *r;
     unsigned int d;
     struct snd_mask old_mask;
     struct snd_interval old_interval;
     bool again;
     int changed, err = 0;
 
     /*
      * Each application of rule has own sequence number.
      *
      * Each member of 'rstamps' array represents the sequence number of
      * recent application of corresponding rule.
      */
     rstamps = kcalloc(constrs->rules_num, sizeof(unsigned int), GFP_KERNEL);
     if (!rstamps)
         return -ENOMEM;
 
     /*
      * Each member of 'vstamps' array represents the sequence number of
      * recent application of rule in which corresponding parameters were
      * changed.
      *
      * In initial state, elements corresponding to parameters requested by
      * a caller is 1. For unrequested parameters, corresponding members
      * have 0 so that the parameters are never changed anymore.
      */
     for (k = 0; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
         vstamps[k] = (params->rmask & PARAM_MASK_BIT(k)) ? 1 : 0;
 
     /* Due to the above design, actual sequence number starts at 2. */
     stamp = 2;
 retry:
     /* Apply all rules in order. */
     again = false;
     for (k = 0; k < constrs->rules_num; k++) {
         r = &constrs->rules[k];
 
         /*
          * Check condition bits of this rule. When the rule has
          * some condition bits, parameter without the bits is
          * never processed. SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP
          * is an example of the condition bits.
          */
         if (r->cond && !(r->cond & params->flags))
             continue;
 
         /*
          * The 'deps' array includes maximum four dependencies
          * to SNDRV_PCM_HW_PARAM_XXXs for this rule. The fifth
          * member of this array is a sentinel and should be
          * negative value.
          *
          * This rule should be processed in this time when dependent
          * parameters were changed at former applications of the other
          * rules.
          */
         for (d = 0; r->deps[d] >= 0; d++) {
             if (vstamps[r->deps[d]] > rstamps[k])
                 break;
         }
         if (r->deps[d] < 0)
             continue;
 
         if (trace_hw_mask_param_enabled()) {
             if (hw_is_mask(r->var))
                 old_mask = *hw_param_mask(params, r->var);
         }
         if (trace_hw_interval_param_enabled()) {
             if (hw_is_interval(r->var))
                 old_interval = *hw_param_interval(params, r->var);
         }
 
         changed = r->func(params, r);
         if (changed < 0) {
             err = changed;
             goto out;
         }
 
         /*
          * When the parameter is changed, notify it to the caller
          * by corresponding returned bit, then preparing for next
          * iteration.
          */
         if (changed && r->var >= 0) {
             if (hw_is_mask(r->var)) {
                 trace_hw_mask_param(substream, r->var,
                     k + 1, &old_mask,
                     hw_param_mask(params, r->var));
             }
             if (hw_is_interval(r->var)) {
                 trace_hw_interval_param(substream, r->var,
                     k + 1, &old_interval,
                     hw_param_interval(params, r->var));
             }
 
             params->cmask |= PARAM_MASK_BIT(r->var);
             vstamps[r->var] = stamp;
             again = true;
         }
 
         rstamps[k] = stamp++;
     }
 
     /* Iterate to evaluate all rules till no parameters are changed. */
     if (again)
         goto retry;
 
  out:
     kfree(rstamps);
     return err;
 }
 
 static int fixup_unreferenced_params(struct snd_pcm_substream *substream,
                      struct snd_pcm_hw_params *params)
 {
     const struct snd_interval *i;
     const struct snd_mask *m;
     int err;
 
     if (!params->msbits) {
         i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
         if (snd_interval_single(i))
             params->msbits = snd_interval_value(i);
     }
 
     if (!params->rate_den) {
         i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
         if (snd_interval_single(i)) {
             params->rate_num = snd_interval_value(i);
             params->rate_den = 1;
         }
     }
 
     if (!params->fifo_size) {
         m = hw_param_mask_c(params, SNDRV_PCM_HW_PARAM_FORMAT);
         i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS);
         if (snd_mask_single(m) && snd_interval_single(i)) {
             err = snd_pcm_ops_ioctl(substream,
                         SNDRV_PCM_IOCTL1_FIFO_SIZE,
                         params);
             if (err < 0)
                 return err;
         }
     }
 
     if (!params->info) {
         params->info = substream->runtime->hw.info;
         params->info &= ~(SNDRV_PCM_INFO_FIFO_IN_FRAMES |
                   SNDRV_PCM_INFO_DRAIN_TRIGGER);
         if (!hw_support_mmap(substream))
             params->info &= ~(SNDRV_PCM_INFO_MMAP |
                       SNDRV_PCM_INFO_MMAP_VALID);
     }
 
     return 0;
 }
 
 int snd_pcm_hw_refine(struct snd_pcm_substream *substream,
               struct snd_pcm_hw_params *params)
 {
     int err;
 
     params->info = 0;
     params->fifo_size = 0;
     if (params->rmask & PARAM_MASK_BIT(SNDRV_PCM_HW_PARAM_SAMPLE_BITS))
         params->msbits = 0;
     if (params->rmask & PARAM_MASK_BIT(SNDRV_PCM_HW_PARAM_RATE)) {
         params->rate_num = 0;
         params->rate_den = 0;
     }
 
     err = constrain_mask_params(substream, params);
     if (err < 0)
         return err;
 
     err = constrain_interval_params(substream, params);
     if (err < 0)
         return err;
 
     err = constrain_params_by_rules(substream, params);
     if (err < 0)
         return err;
 
     params->rmask = 0;
 
     return 0;
 }
 EXPORT_SYMBOL(snd_pcm_hw_refine);
 
 static int snd_pcm_hw_refine_user(struct snd_pcm_substream *substream,
                   struct snd_pcm_hw_params __user * _params)
 {
     struct snd_pcm_hw_params *params;
     int err;
 
     params = memdup_user(_params, sizeof(*params));
     if (IS_ERR(params))
         return PTR_ERR(params);
 
     err = snd_pcm_hw_refine(substream, params);
     if (err < 0)
         goto end;
 
     err = fixup_unreferenced_params(substream, params);
     if (err < 0)
         goto end;
 
     if (copy_to_user(_params, params, sizeof(*params)))
         err = -EFAULT;
 end:
     kfree(params);
     return err;
 }
 
 static int period_to_usecs(struct snd_pcm_runtime *runtime)
 {
     int usecs;
 
     if (! runtime->rate)
         return -1; /* invalid */
 
     /* take 75% of period time as the deadline */
     usecs = (750000 / runtime->rate) * runtime->period_size;
     usecs += ((750000 % runtime->rate) * runtime->period_size) /
         runtime->rate;
 
     return usecs;
 }
 
 static void snd_pcm_set_state(struct snd_pcm_substream *substream,
                   snd_pcm_state_t state)
 {
     snd_pcm_stream_lock_irq(substream);
     if (substream->runtime->status->state != SNDRV_PCM_STATE_DISCONNECTED)
         substream->runtime->status->state = state;
     snd_pcm_stream_unlock_irq(substream);
 }
 
 static inline void snd_pcm_timer_notify(struct snd_pcm_substream *substream,
                     int event)
 {
 #ifdef CONFIG_SND_PCM_TIMER
     if (substream->timer)
         snd_timer_notify(substream->timer, event,
                     &substream->runtime->trigger_tstamp);
 #endif
 }
 
 void snd_pcm_sync_stop(struct snd_pcm_substream *substream, bool sync_irq)
 {
     if (substream->runtime && substream->runtime->stop_operating) {
         substream->runtime->stop_operating = false;
         if (substream->ops && substream->ops->sync_stop)
             substream->ops->sync_stop(substream);
         else if (sync_irq && substream->pcm->card->sync_irq > 0)
             synchronize_irq(substream->pcm->card->sync_irq);
     }
 }
 
 /**
  * snd_pcm_hw_params_choose - choose a configuration defined by @params
  * @pcm: PCM instance
  * @params: the hw_params instance
  *
  * Choose one configuration from configuration space defined by @params.
  * The configuration chosen is that obtained fixing in this order:
  * first access, first format, first subformat, min channels,
  * min rate, min period time, max buffer size, min tick time
  *
  * Return: Zero if successful, or a negative error code on failure.
  */
 static int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
                     struct snd_pcm_hw_params *params)
 {
     static const int vars[] = {
         SNDRV_PCM_HW_PARAM_ACCESS,
         SNDRV_PCM_HW_PARAM_FORMAT,
         SNDRV_PCM_HW_PARAM_SUBFORMAT,
         SNDRV_PCM_HW_PARAM_CHANNELS,
         SNDRV_PCM_HW_PARAM_RATE,
         SNDRV_PCM_HW_PARAM_PERIOD_TIME,
         SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
         SNDRV_PCM_HW_PARAM_TICK_TIME,
         -1
     };
     const int *v;
     struct snd_mask old_mask;
     struct snd_interval old_interval;
     int changed;
 
     for (v = vars; *v != -1; v++) {
         /* Keep old parameter to trace. */
         if (trace_hw_mask_param_enabled()) {
             if (hw_is_mask(*v))
                 old_mask = *hw_param_mask(params, *v);
         }
         if (trace_hw_interval_param_enabled()) {
             if (hw_is_interval(*v))
                 old_interval = *hw_param_interval(params, *v);
         }
         if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
             changed = snd_pcm_hw_param_first(pcm, params, *v, NULL);
         else
             changed = snd_pcm_hw_param_last(pcm, params, *v, NULL);
         if (changed < 0)
             return changed;
         if (changed == 0)
             continue;
 
         /* Trace the changed parameter. */
         if (hw_is_mask(*v)) {
             trace_hw_mask_param(pcm, *v, 0, &old_mask,
                         hw_param_mask(params, *v));
         }
         if (hw_is_interval(*v)) {
             trace_hw_interval_param(pcm, *v, 0, &old_interval,
                         hw_param_interval(params, *v));
         }
     }
 
     return 0;
 }
 
 /* acquire buffer_mutex; if it's in r/w operation, return -EBUSY, otherwise
  * block the further r/w operations
  */
 static int snd_pcm_buffer_access_lock(struct snd_pcm_runtime *runtime)
 {
     if (!atomic_dec_unless_positive(&runtime->buffer_accessing))
         return -EBUSY;
     mutex_lock(&runtime->buffer_mutex);
     return 0; /* keep buffer_mutex, unlocked by below */
 }
 
 /* release buffer_mutex and clear r/w access flag */
 static void snd_pcm_buffer_access_unlock(struct snd_pcm_runtime *runtime)
 {
     mutex_unlock(&runtime->buffer_mutex);
     atomic_inc(&runtime->buffer_accessing);
 }
 
 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 #define is_oss_stream(substream)    ((substream)->oss.oss)
 #else
 #define is_oss_stream(substream)    false
 #endif
 
 static int snd_pcm_hw_params(struct snd_pcm_substream *substream,
                  struct snd_pcm_hw_params *params)
 {
     struct snd_pcm_runtime *runtime;
     int err, usecs;
     unsigned int bits;
     snd_pcm_uframes_t frames;
 
     if (PCM_RUNTIME_CHECK(substream))
         return -ENXIO;
     runtime = substream->runtime;
     err = snd_pcm_buffer_access_lock(runtime);
     if (err < 0)
         return err;
     snd_pcm_stream_lock_irq(substream);
     switch (runtime->status->state) {
     case SNDRV_PCM_STATE_OPEN:
     case SNDRV_PCM_STATE_SETUP:
     case SNDRV_PCM_STATE_PREPARED:
         if (!is_oss_stream(substream) &&
             atomic_read(&substream->mmap_count))
             err = -EBADFD;
         break;
     default:
         err = -EBADFD;
         break;
     }
     snd_pcm_stream_unlock_irq(substream);
     if (err)
         goto unlock;
 
     snd_pcm_sync_stop(substream, true);
 
     params->rmask = ~0U;
     err = snd_pcm_hw_refine(substream, params);
     if (err < 0)
         goto _error;
 
     err = snd_pcm_hw_params_choose(substream, params);
     if (err < 0)
         goto _error;
 
     err = fixup_unreferenced_params(substream, params);
     if (err < 0)
         goto _error;
 
     if (substream->managed_buffer_alloc) {
         err = snd_pcm_lib_malloc_pages(substream,
                            params_buffer_bytes(params));
         if (err < 0)
             goto _error;
         runtime->buffer_changed = err > 0;
     }
 
     if (substream->ops->hw_params != NULL) {
         err = substream->ops->hw_params(substream, params);
         if (err < 0)
             goto _error;
     }
 
     runtime->access = params_access(params);
     runtime->format = params_format(params);
     runtime->subformat = params_subformat(params);
     runtime->channels = params_channels(params);
     runtime->rate = params_rate(params);
     runtime->period_size = params_period_size(params);
     runtime->periods = params_periods(params);
     runtime->buffer_size = params_buffer_size(params);
     runtime->info = params->info;
     runtime->rate_num = params->rate_num;
     runtime->rate_den = params->rate_den;
     runtime->no_period_wakeup =
             (params->info & SNDRV_PCM_INFO_NO_PERIOD_WAKEUP) &&
             (params->flags & SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP);
 
     bits = snd_pcm_format_physical_width(runtime->format);
     runtime->sample_bits = bits;
     bits *= runtime->channels;
     runtime->frame_bits = bits;
     frames = 1;
     while (bits % 8 != 0) {
         bits *= 2;
         frames *= 2;
     }
     runtime->byte_align = bits / 8;
     runtime->min_align = frames;
 
     /* Default sw params */
     runtime->tstamp_mode = SNDRV_PCM_TSTAMP_NONE;
     runtime->period_step = 1;
     runtime->control->avail_min = runtime->period_size;
     runtime->start_threshold = 1;
     runtime->stop_threshold = runtime->buffer_size;
     runtime->silence_threshold = 0;
     runtime->silence_size = 0;
     runtime->boundary = runtime->buffer_size;
     while (runtime->boundary * 2 <= LONG_MAX - runtime->buffer_size)
         runtime->boundary *= 2;
 
     /* clear the buffer for avoiding possible kernel info leaks */
     if (runtime->dma_area && !substream->ops->copy_user) {
         size_t size = runtime->dma_bytes;
 
         if (runtime->info & SNDRV_PCM_INFO_MMAP)
             size = PAGE_ALIGN(size);
         memset(runtime->dma_area, 0, size);
     }
 
     snd_pcm_timer_resolution_change(substream);
     snd_pcm_set_state(substream, SNDRV_PCM_STATE_SETUP);
 
     if (cpu_latency_qos_request_active(&substream->latency_pm_qos_req))
         cpu_latency_qos_remove_request(&substream->latency_pm_qos_req);
     usecs = period_to_usecs(runtime);
     if (usecs >= 0)
         cpu_latency_qos_add_request(&substream->latency_pm_qos_req,
                         usecs);
     err = 0;
  _error:
     if (err) {
         /* hardware might be unusable from this time,
          * so we force application to retry to set
          * the correct hardware parameter settings
          */
         snd_pcm_set_state(substream, SNDRV_PCM_STATE_OPEN);
         if (substream->ops->hw_free != NULL)
             substream->ops->hw_free(substream);
         if (substream->managed_buffer_alloc)
             snd_pcm_lib_free_pages(substream);
     }
  unlock:
     snd_pcm_buffer_access_unlock(runtime);
     return err;
 }
 
 static int snd_pcm_hw_params_user(struct snd_pcm_substream *substream,
                   struct snd_pcm_hw_params __user * _params)
 {
     struct snd_pcm_hw_params *params;
     int err;
 
     params = memdup_user(_params, sizeof(*params));
     if (IS_ERR(params))
         return PTR_ERR(params);
 
     err = snd_pcm_hw_params(substream, params);
     if (err < 0)
         goto end;
 
     if (copy_to_user(_params, params, sizeof(*params)))
         err = -EFAULT;
 end:
     kfree(params);
     return err;
 }
 
 static int do_hw_free(struct snd_pcm_substream *substream)
 {
     int result = 0;
 
     snd_pcm_sync_stop(substream, true);
     if (substream->ops->hw_free)
         result = substream->ops->hw_free(substream);
     if (substream->managed_buffer_alloc)
         snd_pcm_lib_free_pages(substream);
     return result;
 }
 
 static int snd_pcm_hw_free(struct snd_pcm_substream *substream)
 {
     struct snd_pcm_runtime *runtime;
     int result = 0;
 
     if (PCM_RUNTIME_CHECK(substream))
         return -ENXIO;
     runtime = substream->runtime;
     result = snd_pcm_buffer_access_lock(runtime);
     if (result < 0)
         return result;
     snd_pcm_stream_lock_irq(substream);
     switch (runtime->status->state) {
     case SNDRV_PCM_STATE_SETUP:
     case SNDRV_PCM_STATE_PREPARED:
         if (atomic_read(&substream->mmap_count))
             result = -EBADFD;
         break;
     default:
         result = -EBADFD;
         break;
     }
     snd_pcm_stream_unlock_irq(substream);
     if (result)
         goto unlock;
     result = do_hw_free(substream);
     snd_pcm_set_state(substream, SNDRV_PCM_STATE_OPEN);
     cpu_latency_qos_remove_request(&substream->latency_pm_qos_req);
  unlock:
     snd_pcm_buffer_access_unlock(runtime);
     return result;
 }
 
 static int snd_pcm_sw_params(struct snd_pcm_substream *substream,
                  struct snd_pcm_sw_params *params)
 {
     struct snd_pcm_runtime *runtime;
     int err;
 
     if (PCM_RUNTIME_CHECK(substream))
         return -ENXIO;
     runtime = substream->runtime;
     snd_pcm_stream_lock_irq(substream);
     if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
         snd_pcm_stream_unlock_irq(substream);
         return -EBADFD;
     }
     snd_pcm_stream_unlock_irq(substream);
 
     if (params->tstamp_mode < 0 ||
         params->tstamp_mode > SNDRV_PCM_TSTAMP_LAST)
         return -EINVAL;
     if (params->proto >= SNDRV_PROTOCOL_VERSION(2, 0, 12) &&
         params->tstamp_type > SNDRV_PCM_TSTAMP_TYPE_LAST)
         return -EINVAL;
     if (params->avail_min == 0)
         return -EINVAL;
     if (params->silence_size >= runtime->boundary) {
         if (params->silence_threshold != 0)
             return -EINVAL;
     } else {
         if (params->silence_size > params->silence_threshold)
             return -EINVAL;
         if (params->silence_threshold > runtime->buffer_size)
             return -EINVAL;
     }
     err = 0;
     snd_pcm_stream_lock_irq(substream);
     runtime->tstamp_mode = params->tstamp_mode;
     if (params->proto >= SNDRV_PROTOCOL_VERSION(2, 0, 12))
         runtime->tstamp_type = params->tstamp_type;
     runtime->period_step = params->period_step;
     runtime->control->avail_min = params->avail_min;
     runtime->start_threshold = params->start_threshold;
     runtime->stop_threshold = params->stop_threshold;
     runtime->silence_threshold = params->silence_threshold;
     runtime->silence_size = params->silence_size;
         params->boundary = runtime->boundary;
     if (snd_pcm_running(substream)) {
         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
             runtime->silence_size > 0)
             snd_pcm_playback_silence(substream, ULONG_MAX);
         err = snd_pcm_update_state(substream, runtime);
     }
     snd_pcm_stream_unlock_irq(substream);
     return err;
 }
 
 static int snd_pcm_sw_params_user(struct snd_pcm_substream *substream,
                   struct snd_pcm_sw_params __user * _params)
 {
     struct snd_pcm_sw_params params;
     int err;
     if (copy_from_user(&params, _params, sizeof(params)))
         return -EFAULT;
     err = snd_pcm_sw_params(substream, &params);
     if (copy_to_user(_params, &params, sizeof(params)))
         return -EFAULT;
     return err;
 }
 
 static inline snd_pcm_uframes_t
 snd_pcm_calc_delay(struct snd_pcm_substream *substream)
 {
     snd_pcm_uframes_t delay;
 
     if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
         delay = snd_pcm_playback_hw_avail(substream->runtime);
     else
         delay = snd_pcm_capture_avail(substream->runtime);
     return delay + substream->runtime->delay;
 }
 
 int snd_pcm_status64(struct snd_pcm_substream *substream,
              struct snd_pcm_status64 *status)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
 
     snd_pcm_stream_lock_irq(substream);
 
     snd_pcm_unpack_audio_tstamp_config(status->audio_tstamp_data,
                     &runtime->audio_tstamp_config);
 
     /* backwards compatible behavior */
     if (runtime->audio_tstamp_config.type_requested ==
         SNDRV_PCM_AUDIO_TSTAMP_TYPE_COMPAT) {
         if (runtime->hw.info & SNDRV_PCM_INFO_HAS_WALL_CLOCK)
             runtime->audio_tstamp_config.type_requested =
                 SNDRV_PCM_AUDIO_TSTAMP_TYPE_LINK;
         else
             runtime->audio_tstamp_config.type_requested =
                 SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT;
         runtime->audio_tstamp_report.valid = 0;
     } else
         runtime->audio_tstamp_report.valid = 1;
 
     status->state = runtime->status->state;
     status->suspended_state = runtime->status->suspended_state;
     if (status->state == SNDRV_PCM_STATE_OPEN)
         goto _end;
     status->trigger_tstamp_sec = runtime->trigger_tstamp.tv_sec;
     status->trigger_tstamp_nsec = runtime->trigger_tstamp.tv_nsec;
     if (snd_pcm_running(substream)) {
         snd_pcm_update_hw_ptr(substream);
         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
             status->tstamp_sec = runtime->status->tstamp.tv_sec;
             status->tstamp_nsec =
                 runtime->status->tstamp.tv_nsec;
             status->driver_tstamp_sec =
                 runtime->driver_tstamp.tv_sec;
             status->driver_tstamp_nsec =
                 runtime->driver_tstamp.tv_nsec;
             status->audio_tstamp_sec =
                 runtime->status->audio_tstamp.tv_sec;
             status->audio_tstamp_nsec =
                 runtime->status->audio_tstamp.tv_nsec;
             if (runtime->audio_tstamp_report.valid == 1)
                 /* backwards compatibility, no report provided in COMPAT mode */
                 snd_pcm_pack_audio_tstamp_report(&status->audio_tstamp_data,
                                 &status->audio_tstamp_accuracy,
                                 &runtime->audio_tstamp_report);
 
             goto _tstamp_end;
         }
     } else {
         /* get tstamp only in fallback mode and only if enabled */
         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
             struct timespec64 tstamp;
 
             snd_pcm_gettime(runtime, &tstamp);
             status->tstamp_sec = tstamp.tv_sec;
             status->tstamp_nsec = tstamp.tv_nsec;
         }
     }
  _tstamp_end:
     status->appl_ptr = runtime->control->appl_ptr;
     status->hw_ptr = runtime->status->hw_ptr;
     status->avail = snd_pcm_avail(substream);
     status->delay = snd_pcm_running(substream) ?
         snd_pcm_calc_delay(substream) : 0;
     status->avail_max = runtime->avail_max;
     status->overrange = runtime->overrange;
     runtime->avail_max = 0;
     runtime->overrange = 0;
  _end:
     snd_pcm_stream_unlock_irq(substream);
     return 0;
 }
 
 static int snd_pcm_status_user64(struct snd_pcm_substream *substream,
                  struct snd_pcm_status64 __user * _status,
                  bool ext)
 {
     struct snd_pcm_status64 status;
     int res;
 
     memset(&status, 0, sizeof(status));
     /*
      * with extension, parameters are read/write,
      * get audio_tstamp_data from user,
      * ignore rest of status structure
      */
     if (ext && get_user(status.audio_tstamp_data,
                 (u32 __user *)(&_status->audio_tstamp_data)))
         return -EFAULT;
     res = snd_pcm_status64(substream, &status);
     if (res < 0)
         return res;
     if (copy_to_user(_status, &status, sizeof(status)))
         return -EFAULT;
     return 0;
 }
 
 static int snd_pcm_status_user32(struct snd_pcm_substream *substream,
                  struct snd_pcm_status32 __user * _status,
                  bool ext)
 {
     struct snd_pcm_status64 status64;
     struct snd_pcm_status32 status32;
     int res;
 
     memset(&status64, 0, sizeof(status64));
     memset(&status32, 0, sizeof(status32));
     /*
      * with extension, parameters are read/write,
      * get audio_tstamp_data from user,
      * ignore rest of status structure
      */
     if (ext && get_user(status64.audio_tstamp_data,
                 (u32 __user *)(&_status->audio_tstamp_data)))
         return -EFAULT;
     res = snd_pcm_status64(substream, &status64);
     if (res < 0)
         return res;
 
     status32 = (struct snd_pcm_status32) {
         .state = status64.state,
         .trigger_tstamp_sec = status64.trigger_tstamp_sec,
         .trigger_tstamp_nsec = status64.trigger_tstamp_nsec,
         .tstamp_sec = status64.tstamp_sec,
         .tstamp_nsec = status64.tstamp_nsec,
         .appl_ptr = status64.appl_ptr,
         .hw_ptr = status64.hw_ptr,
         .delay = status64.delay,
         .avail = status64.avail,
         .avail_max = status64.avail_max,
         .overrange = status64.overrange,
         .suspended_state = status64.suspended_state,
         .audio_tstamp_data = status64.audio_tstamp_data,
         .audio_tstamp_sec = status64.audio_tstamp_sec,
         .audio_tstamp_nsec = status64.audio_tstamp_nsec,
         .driver_tstamp_sec = status64.audio_tstamp_sec,
         .driver_tstamp_nsec = status64.audio_tstamp_nsec,
         .audio_tstamp_accuracy = status64.audio_tstamp_accuracy,
     };
 
     if (copy_to_user(_status, &status32, sizeof(status32)))
         return -EFAULT;
 
     return 0;
 }
 
 static int snd_pcm_channel_info(struct snd_pcm_substream *substream,
                 struct snd_pcm_channel_info * info)
 {
     struct snd_pcm_runtime *runtime;
     unsigned int channel;
     
     channel = info->channel;
     runtime = substream->runtime;
     snd_pcm_stream_lock_irq(substream);
     if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
         snd_pcm_stream_unlock_irq(substream);
         return -EBADFD;
     }
     snd_pcm_stream_unlock_irq(substream);
     if (channel >= runtime->channels)
         return -EINVAL;
     memset(info, 0, sizeof(*info));
     info->channel = channel;
     return snd_pcm_ops_ioctl(substream, SNDRV_PCM_IOCTL1_CHANNEL_INFO, info);
 }
 
 static int snd_pcm_channel_info_user(struct snd_pcm_substream *substream,
                      struct snd_pcm_channel_info __user * _info)
 {
     struct snd_pcm_channel_info info;
     int res;
     
     if (copy_from_user(&info, _info, sizeof(info)))
         return -EFAULT;
     res = snd_pcm_channel_info(substream, &info);
     if (res < 0)
         return res;
     if (copy_to_user(_info, &info, sizeof(info)))
         return -EFAULT;
     return 0;
 }
 
 static void snd_pcm_trigger_tstamp(struct snd_pcm_substream *substream)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     if (runtime->trigger_master == NULL)
         return;
     if (runtime->trigger_master == substream) {
         if (!runtime->trigger_tstamp_latched)
             snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
     } else {
         snd_pcm_trigger_tstamp(runtime->trigger_master);
         runtime->trigger_tstamp = runtime->trigger_master->runtime->trigger_tstamp;
     }
     runtime->trigger_master = NULL;
 }
 
 #define ACTION_ARG_IGNORE   (__force snd_pcm_state_t)0
 
 struct action_ops {
     int (*pre_action)(struct snd_pcm_substream *substream,
               snd_pcm_state_t state);
     int (*do_action)(struct snd_pcm_substream *substream,
              snd_pcm_state_t state);
     void (*undo_action)(struct snd_pcm_substream *substream,
                 snd_pcm_state_t state);
     void (*post_action)(struct snd_pcm_substream *substream,
                 snd_pcm_state_t state);
 };
 
 /*
  *  this functions is core for handling of linked stream
  *  Note: the stream state might be changed also on failure
  *  Note2: call with calling stream lock + link lock
  */
 static int snd_pcm_action_group(const struct action_ops *ops,
                 struct snd_pcm_substream *substream,
                 snd_pcm_state_t state,
                 bool stream_lock)
 {
     struct snd_pcm_substream *s = NULL;
     struct snd_pcm_substream *s1;
     int res = 0, depth = 1;
 
     snd_pcm_group_for_each_entry(s, substream) {
         if (s != substream) {
             if (!stream_lock)
                 mutex_lock_nested(&s->runtime->buffer_mutex, depth);
             else if (s->pcm->nonatomic)
                 mutex_lock_nested(&s->self_group.mutex, depth);
             else
                 spin_lock_nested(&s->self_group.lock, depth);
             depth++;
         }
         res = ops->pre_action(s, state);
         if (res < 0)
             goto _unlock;
     }
     snd_pcm_group_for_each_entry(s, substream) {
         res = ops->do_action(s, state);
         if (res < 0) {
             if (ops->undo_action) {
                 snd_pcm_group_for_each_entry(s1, substream) {
                     if (s1 == s) /* failed stream */
                         break;
                     ops->undo_action(s1, state);
                 }
             }
             s = NULL; /* unlock all */
             goto _unlock;
         }
     }
     snd_pcm_group_for_each_entry(s, substream) {
         ops->post_action(s, state);
     }
  _unlock:
     /* unlock streams */
     snd_pcm_group_for_each_entry(s1, substream) {
         if (s1 != substream) {
             if (!stream_lock)
                 mutex_unlock(&s1->runtime->buffer_mutex);
             else if (s1->pcm->nonatomic)
                 mutex_unlock(&s1->self_group.mutex);
             else
                 spin_unlock(&s1->self_group.lock);
         }
         if (s1 == s)    /* end */
             break;
     }
     return res;
 }
 
 /*
  *  Note: call with stream lock
  */
 static int snd_pcm_action_single(const struct action_ops *ops,
                  struct snd_pcm_substream *substream,
                  snd_pcm_state_t state)
 {
     int res;
     
     res = ops->pre_action(substream, state);
     if (res < 0)
         return res;
     res = ops->do_action(substream, state);
     if (res == 0)
         ops->post_action(substream, state);
     else if (ops->undo_action)
         ops->undo_action(substream, state);
     return res;
 }
 
 static void snd_pcm_group_assign(struct snd_pcm_substream *substream,
                  struct snd_pcm_group *new_group)
 {
     substream->group = new_group;
     list_move(&substream->link_list, &new_group->substreams);
 }
 
 /*
  * Unref and unlock the group, but keep the stream lock;
  * when the group becomes empty and no longer referred, destroy itself
  */
 static void snd_pcm_group_unref(struct snd_pcm_group *group,
                 struct snd_pcm_substream *substream)
 {
     bool do_free;
 
     if (!group)
         return;
     do_free = refcount_dec_and_test(&group->refs);
     snd_pcm_group_unlock(group, substream->pcm->nonatomic);
     if (do_free)
         kfree(group);
 }
 
 /*
  * Lock the group inside a stream lock and reference it;
  * return the locked group object, or NULL if not linked
  */
 static struct snd_pcm_group *
 snd_pcm_stream_group_ref(struct snd_pcm_substream *substream)
 {
     bool nonatomic = substream->pcm->nonatomic;
     struct snd_pcm_group *group;
     bool trylock;
 
     for (;;) {
         if (!snd_pcm_stream_linked(substream))
             return NULL;
         group = substream->group;
         /* block freeing the group object */
         refcount_inc(&group->refs);
 
         trylock = nonatomic ? mutex_trylock(&group->mutex) :
             spin_trylock(&group->lock);
         if (trylock)
             break; /* OK */
 
         /* re-lock for avoiding ABBA deadlock */
         snd_pcm_stream_unlock(substream);
         snd_pcm_group_lock(group, nonatomic);
         snd_pcm_stream_lock(substream);
 
         /* check the group again; the above opens a small race window */
         if (substream->group == group)
             break; /* OK */
         /* group changed, try again */
         snd_pcm_group_unref(group, substream);
     }
     return group;
 }
 
 /*
  *  Note: call with stream lock
  */
 static int snd_pcm_action(const struct action_ops *ops,
               struct snd_pcm_substream *substream,
               snd_pcm_state_t state)
 {
     struct snd_pcm_group *group;
     int res;
 
     group = snd_pcm_stream_group_ref(substream);
     if (group)
         res = snd_pcm_action_group(ops, substream, state, true);
     else
         res = snd_pcm_action_single(ops, substream, state);
     snd_pcm_group_unref(group, substream);
     return res;
 }
 
 /*
  *  Note: don't use any locks before
  */
 static int snd_pcm_action_lock_irq(const struct action_ops *ops,
                    struct snd_pcm_substream *substream,
                    snd_pcm_state_t state)
 {
     int res;
 
     snd_pcm_stream_lock_irq(substream);
     res = snd_pcm_action(ops, substream, state);
     snd_pcm_stream_unlock_irq(substream);
     return res;
 }
 
 /*
  */
 static int snd_pcm_action_nonatomic(const struct action_ops *ops,
                     struct snd_pcm_substream *substream,
                     snd_pcm_state_t state)
 {
     int res;
 
     /* Guarantee the group members won't change during non-atomic action */
     down_read(&snd_pcm_link_rwsem);
     res = snd_pcm_buffer_access_lock(substream->runtime);
     if (res < 0)
         goto unlock;
     if (snd_pcm_stream_linked(substream))
         res = snd_pcm_action_group(ops, substream, state, false);
     else
         res = snd_pcm_action_single(ops, substream, state);
     snd_pcm_buffer_access_unlock(substream->runtime);
  unlock:
     up_read(&snd_pcm_link_rwsem);
     return res;
 }
 
 /*
  * start callbacks
  */
 static int snd_pcm_pre_start(struct snd_pcm_substream *substream,
                  snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     if (runtime->status->state != SNDRV_PCM_STATE_PREPARED)
         return -EBADFD;
     if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
         !snd_pcm_playback_data(substream))
         return -EPIPE;
     runtime->trigger_tstamp_latched = false;
     runtime->trigger_master = substream;
     return 0;
 }
 
 static int snd_pcm_do_start(struct snd_pcm_substream *substream,
                 snd_pcm_state_t state)
 {
     if (substream->runtime->trigger_master != substream)
         return 0;
     return substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_START);
 }
 
 static void snd_pcm_undo_start(struct snd_pcm_substream *substream,
                    snd_pcm_state_t state)
 {
     if (substream->runtime->trigger_master == substream)
         substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_STOP);
 }
 
 static void snd_pcm_post_start(struct snd_pcm_substream *substream,
                    snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     snd_pcm_trigger_tstamp(substream);
     runtime->hw_ptr_jiffies = jiffies;
     runtime->hw_ptr_buffer_jiffies = (runtime->buffer_size * HZ) / 
                                 runtime->rate;
     runtime->status->state = state;
     if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
         runtime->silence_size > 0)
         snd_pcm_playback_silence(substream, ULONG_MAX);
     snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MSTART);
 }
 
 static const struct action_ops snd_pcm_action_start = {
     .pre_action = snd_pcm_pre_start,
     .do_action = snd_pcm_do_start,
     .undo_action = snd_pcm_undo_start,
     .post_action = snd_pcm_post_start
 };
 
 /**
  * snd_pcm_start - start all linked streams
  * @substream: the PCM substream instance
  *
  * Return: Zero if successful, or a negative error code.
  * The stream lock must be acquired before calling this function.
  */
 int snd_pcm_start(struct snd_pcm_substream *substream)
 {
     return snd_pcm_action(&snd_pcm_action_start, substream,
                   SNDRV_PCM_STATE_RUNNING);
 }
 
 /* take the stream lock and start the streams */
 static int snd_pcm_start_lock_irq(struct snd_pcm_substream *substream)
 {
     return snd_pcm_action_lock_irq(&snd_pcm_action_start, substream,
                        SNDRV_PCM_STATE_RUNNING);
 }
 
 /*
  * stop callbacks
  */
 static int snd_pcm_pre_stop(struct snd_pcm_substream *substream,
                 snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
         return -EBADFD;
     runtime->trigger_master = substream;
     return 0;
 }
 
 static int snd_pcm_do_stop(struct snd_pcm_substream *substream,
                snd_pcm_state_t state)
 {
     if (substream->runtime->trigger_master == substream &&
         snd_pcm_running(substream)) {
         substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_STOP);
         substream->runtime->stop_operating = true;
     }
     return 0; /* unconditionally stop all substreams */
 }
 
 static void snd_pcm_post_stop(struct snd_pcm_substream *substream,
                   snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     if (runtime->status->state != state) {
         snd_pcm_trigger_tstamp(substream);
         runtime->status->state = state;
         snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MSTOP);
     }
     wake_up(&runtime->sleep);
     wake_up(&runtime->tsleep);
 }
 
 static const struct action_ops snd_pcm_action_stop = {
     .pre_action = snd_pcm_pre_stop,
     .do_action = snd_pcm_do_stop,
     .post_action = snd_pcm_post_stop
 };
 
 /**
  * snd_pcm_stop - try to stop all running streams in the substream group
  * @substream: the PCM substream instance
  * @state: PCM state after stopping the stream
  *
  * The state of each stream is then changed to the given state unconditionally.
  *
  * Return: Zero if successful, or a negative error code.
  */
 int snd_pcm_stop(struct snd_pcm_substream *substream, snd_pcm_state_t state)
 {
     return snd_pcm_action(&snd_pcm_action_stop, substream, state);
 }
 EXPORT_SYMBOL(snd_pcm_stop);
 
 /**
  * snd_pcm_drain_done - stop the DMA only when the given stream is playback
  * @substream: the PCM substream
  *
  * After stopping, the state is changed to SETUP.
  * Unlike snd_pcm_stop(), this affects only the given stream.
  *
  * Return: Zero if successful, or a negative error code.
  */
 int snd_pcm_drain_done(struct snd_pcm_substream *substream)
 {
     return snd_pcm_action_single(&snd_pcm_action_stop, substream,
                      SNDRV_PCM_STATE_SETUP);
 }
 
 /**
  * snd_pcm_stop_xrun - stop the running streams as XRUN
  * @substream: the PCM substream instance
  *
  * This stops the given running substream (and all linked substreams) as XRUN.
  * Unlike snd_pcm_stop(), this function takes the substream lock by itself.
  *
  * Return: Zero if successful, or a negative error code.
  */
 int snd_pcm_stop_xrun(struct snd_pcm_substream *substream)
 {
     unsigned long flags;
 
     snd_pcm_stream_lock_irqsave(substream, flags);
     if (substream->runtime && snd_pcm_running(substream))
         __snd_pcm_xrun(substream);
     snd_pcm_stream_unlock_irqrestore(substream, flags);
     return 0;
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stop_xrun);
 
 /*
  * pause callbacks: pass boolean (to start pause or resume) as state argument
  */
 #define pause_pushed(state) (__force bool)(state)
 
 static int snd_pcm_pre_pause(struct snd_pcm_substream *substream,
                  snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     if (!(runtime->info & SNDRV_PCM_INFO_PAUSE))
         return -ENOSYS;
     if (pause_pushed(state)) {
         if (runtime->status->state != SNDRV_PCM_STATE_RUNNING)
             return -EBADFD;
     } else if (runtime->status->state != SNDRV_PCM_STATE_PAUSED)
         return -EBADFD;
     runtime->trigger_master = substream;
     return 0;
 }
 
 static int snd_pcm_do_pause(struct snd_pcm_substream *substream,
                 snd_pcm_state_t state)
 {
     if (substream->runtime->trigger_master != substream)
         return 0;
     /* some drivers might use hw_ptr to recover from the pause -
        update the hw_ptr now */
     if (pause_pushed(state))
         snd_pcm_update_hw_ptr(substream);
     /* The jiffies check in snd_pcm_update_hw_ptr*() is done by
      * a delta between the current jiffies, this gives a large enough
      * delta, effectively to skip the check once.
      */
     substream->runtime->hw_ptr_jiffies = jiffies - HZ * 1000;
     return substream->ops->trigger(substream,
                        pause_pushed(state) ?
                        SNDRV_PCM_TRIGGER_PAUSE_PUSH :
                        SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
 }
 
 static void snd_pcm_undo_pause(struct snd_pcm_substream *substream,
                    snd_pcm_state_t state)
 {
     if (substream->runtime->trigger_master == substream)
         substream->ops->trigger(substream,
                     pause_pushed(state) ?
                     SNDRV_PCM_TRIGGER_PAUSE_RELEASE :
                     SNDRV_PCM_TRIGGER_PAUSE_PUSH);
 }
 
 static void snd_pcm_post_pause(struct snd_pcm_substream *substream,
                    snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     snd_pcm_trigger_tstamp(substream);
     if (pause_pushed(state)) {
         runtime->status->state = SNDRV_PCM_STATE_PAUSED;
         snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MPAUSE);
         wake_up(&runtime->sleep);
         wake_up(&runtime->tsleep);
     } else {
         runtime->status->state = SNDRV_PCM_STATE_RUNNING;
         snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MCONTINUE);
     }
 }
 
 static const struct action_ops snd_pcm_action_pause = {
     .pre_action = snd_pcm_pre_pause,
     .do_action = snd_pcm_do_pause,
     .undo_action = snd_pcm_undo_pause,
     .post_action = snd_pcm_post_pause
 };
 
 /*
  * Push/release the pause for all linked streams.
  */
 static int snd_pcm_pause(struct snd_pcm_substream *substream, bool push)
 {
     return snd_pcm_action(&snd_pcm_action_pause, substream,
                   (__force snd_pcm_state_t)push);
 }
 
 static int snd_pcm_pause_lock_irq(struct snd_pcm_substream *substream,
                   bool push)
 {
     return snd_pcm_action_lock_irq(&snd_pcm_action_pause, substream,
                        (__force snd_pcm_state_t)push);
 }
 
 #ifdef CONFIG_PM
 /* suspend callback: state argument ignored */
 
 static int snd_pcm_pre_suspend(struct snd_pcm_substream *substream,
                    snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     switch (runtime->status->state) {
     case SNDRV_PCM_STATE_SUSPENDED:
         return -EBUSY;
     /* unresumable PCM state; return -EBUSY for skipping suspend */
     case SNDRV_PCM_STATE_OPEN:
     case SNDRV_PCM_STATE_SETUP:
     case SNDRV_PCM_STATE_DISCONNECTED:
         return -EBUSY;
     }
     runtime->trigger_master = substream;
     return 0;
 }
 
 static int snd_pcm_do_suspend(struct snd_pcm_substream *substream,
                   snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     if (runtime->trigger_master != substream)
         return 0;
     if (! snd_pcm_running(substream))
         return 0;
     substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_SUSPEND);
     runtime->stop_operating = true;
     return 0; /* suspend unconditionally */
 }
 
 static void snd_pcm_post_suspend(struct snd_pcm_substream *substream,
                  snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     snd_pcm_trigger_tstamp(substream);
     runtime->status->suspended_state = runtime->status->state;
     runtime->status->state = SNDRV_PCM_STATE_SUSPENDED;
     snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MSUSPEND);
     wake_up(&runtime->sleep);
     wake_up(&runtime->tsleep);
 }
 
 static const struct action_ops snd_pcm_action_suspend = {
     .pre_action = snd_pcm_pre_suspend,
     .do_action = snd_pcm_do_suspend,
     .post_action = snd_pcm_post_suspend
 };
 
 /*
  * snd_pcm_suspend - trigger SUSPEND to all linked streams
  * @substream: the PCM substream
  *
  * After this call, all streams are changed to SUSPENDED state.
  *
  * Return: Zero if successful, or a negative error code.
  */
 static int snd_pcm_suspend(struct snd_pcm_substream *substream)
 {
     int err;
     unsigned long flags;
 
     snd_pcm_stream_lock_irqsave(substream, flags);
     err = snd_pcm_action(&snd_pcm_action_suspend, substream,
                  ACTION_ARG_IGNORE);
     snd_pcm_stream_unlock_irqrestore(substream, flags);
     return err;
 }
 
 /**
  * snd_pcm_suspend_all - trigger SUSPEND to all substreams in the given pcm
  * @pcm: the PCM instance
  *
  * After this call, all streams are changed to SUSPENDED state.
  *
  * Return: Zero if successful (or @pcm is %NULL), or a negative error code.
  */
 int snd_pcm_suspend_all(struct snd_pcm *pcm)
 {
     struct snd_pcm_substream *substream;
     int stream, err = 0;
 
     if (! pcm)
         return 0;
 
     for_each_pcm_substream(pcm, stream, substream) {
         /* FIXME: the open/close code should lock this as well */
         if (!substream->runtime)
             continue;
 
         /*
          * Skip BE dai link PCM's that are internal and may
          * not have their substream ops set.
          */
         if (!substream->ops)
             continue;
 
         err = snd_pcm_suspend(substream);
         if (err < 0 && err != -EBUSY)
             return err;
     }
 
     for_each_pcm_substream(pcm, stream, substream)
         snd_pcm_sync_stop(substream, false);
 
     return 0;
 }
 EXPORT_SYMBOL(snd_pcm_suspend_all);
 
 /* resume callbacks: state argument ignored */
 
 static int snd_pcm_pre_resume(struct snd_pcm_substream *substream,
                   snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     if (!(runtime->info & SNDRV_PCM_INFO_RESUME))
         return -ENOSYS;
     runtime->trigger_master = substream;
     return 0;
 }
 
 static int snd_pcm_do_resume(struct snd_pcm_substream *substream,
                  snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     if (runtime->trigger_master != substream)
         return 0;
     /* DMA not running previously? */
     if (runtime->status->suspended_state != SNDRV_PCM_STATE_RUNNING &&
         (runtime->status->suspended_state != SNDRV_PCM_STATE_DRAINING ||
          substream->stream != SNDRV_PCM_STREAM_PLAYBACK))
         return 0;
     return substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_RESUME);
 }
 
 static void snd_pcm_undo_resume(struct snd_pcm_substream *substream,
                 snd_pcm_state_t state)
 {
     if (substream->runtime->trigger_master == substream &&
         snd_pcm_running(substream))
         substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_SUSPEND);
 }
 
 static void snd_pcm_post_resume(struct snd_pcm_substream *substream,
                 snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     snd_pcm_trigger_tstamp(substream);
     runtime->status->state = runtime->status->suspended_state;
     snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MRESUME);
 }
 
 static const struct action_ops snd_pcm_action_resume = {
     .pre_action = snd_pcm_pre_resume,
     .do_action = snd_pcm_do_resume,
     .undo_action = snd_pcm_undo_resume,
     .post_action = snd_pcm_post_resume
 };
 
 static int snd_pcm_resume(struct snd_pcm_substream *substream)
 {
     return snd_pcm_action_lock_irq(&snd_pcm_action_resume, substream,
                        ACTION_ARG_IGNORE);
 }
 
 #else
 
 static int snd_pcm_resume(struct snd_pcm_substream *substream)
 {
     return -ENOSYS;
 }
 
 #endif /* CONFIG_PM */
 
 /*
  * xrun ioctl
  *
  * Change the RUNNING stream(s) to XRUN state.
  */
 static int snd_pcm_xrun(struct snd_pcm_substream *substream)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     int result;
 
     snd_pcm_stream_lock_irq(substream);
     switch (runtime->status->state) {
     case SNDRV_PCM_STATE_XRUN:
         result = 0; /* already there */
         break;
     case SNDRV_PCM_STATE_RUNNING:
         __snd_pcm_xrun(substream);
         result = 0;
         break;
     default:
         result = -EBADFD;
     }
     snd_pcm_stream_unlock_irq(substream);
     return result;
 }
 
 /*
  * reset ioctl
  */
 /* reset callbacks:  state argument ignored */
 static int snd_pcm_pre_reset(struct snd_pcm_substream *substream,
                  snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     switch (runtime->status->state) {
     case SNDRV_PCM_STATE_RUNNING:
     case SNDRV_PCM_STATE_PREPARED:
     case SNDRV_PCM_STATE_PAUSED:
     case SNDRV_PCM_STATE_SUSPENDED:
         return 0;
     default:
         return -EBADFD;
     }
 }
 
 static int snd_pcm_do_reset(struct snd_pcm_substream *substream,
                 snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     int err = snd_pcm_ops_ioctl(substream, SNDRV_PCM_IOCTL1_RESET, NULL);
     if (err < 0)
         return err;
     snd_pcm_stream_lock_irq(substream);
     runtime->hw_ptr_base = 0;
     runtime->hw_ptr_interrupt = runtime->status->hw_ptr -
         runtime->status->hw_ptr % runtime->period_size;
     runtime->silence_start = runtime->status->hw_ptr;
     runtime->silence_filled = 0;
     snd_pcm_stream_unlock_irq(substream);
     return 0;
 }
 
 static void snd_pcm_post_reset(struct snd_pcm_substream *substream,
                    snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     snd_pcm_stream_lock_irq(substream);
     runtime->control->appl_ptr = runtime->status->hw_ptr;
     if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
         runtime->silence_size > 0)
         snd_pcm_playback_silence(substream, ULONG_MAX);
     snd_pcm_stream_unlock_irq(substream);
 }
 
 static const struct action_ops snd_pcm_action_reset = {
     .pre_action = snd_pcm_pre_reset,
     .do_action = snd_pcm_do_reset,
     .post_action = snd_pcm_post_reset
 };
 
 static int snd_pcm_reset(struct snd_pcm_substream *substream)
 {
     return snd_pcm_action_nonatomic(&snd_pcm_action_reset, substream,
                     ACTION_ARG_IGNORE);
 }
 
 /*
  * prepare ioctl
  */
 /* pass f_flags as state argument */
 static int snd_pcm_pre_prepare(struct snd_pcm_substream *substream,
                    snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     int f_flags = (__force int)state;
 
     if (runtime->status->state == SNDRV_PCM_STATE_OPEN ||
         runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
         return -EBADFD;
     if (snd_pcm_running(substream))
         return -EBUSY;
     substream->f_flags = f_flags;
     return 0;
 }
 
 static int snd_pcm_do_prepare(struct snd_pcm_substream *substream,
                   snd_pcm_state_t state)
 {
     int err;
     snd_pcm_sync_stop(substream, true);
     err = substream->ops->prepare(substream);
     if (err < 0)
         return err;
     return snd_pcm_do_reset(substream, state);
 }
 
 static void snd_pcm_post_prepare(struct snd_pcm_substream *substream,
                  snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     runtime->control->appl_ptr = runtime->status->hw_ptr;
     snd_pcm_set_state(substream, SNDRV_PCM_STATE_PREPARED);
 }
 
 static const struct action_ops snd_pcm_action_prepare = {
     .pre_action = snd_pcm_pre_prepare,
     .do_action = snd_pcm_do_prepare,
     .post_action = snd_pcm_post_prepare
 };
 
 /**
  * snd_pcm_prepare - prepare the PCM substream to be triggerable
  * @substream: the PCM substream instance
  * @file: file to refer f_flags
  *
  * Return: Zero if successful, or a negative error code.
  */
 static int snd_pcm_prepare(struct snd_pcm_substream *substream,
                struct file *file)
 {
     int f_flags;
 
     if (file)
         f_flags = file->f_flags;
     else
         f_flags = substream->f_flags;
 
     snd_pcm_stream_lock_irq(substream);
     switch (substream->runtime->status->state) {
     case SNDRV_PCM_STATE_PAUSED:
         snd_pcm_pause(substream, false);
         fallthrough;
     case SNDRV_PCM_STATE_SUSPENDED:
         snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
         break;
     }
     snd_pcm_stream_unlock_irq(substream);
 
     return snd_pcm_action_nonatomic(&snd_pcm_action_prepare,
                     substream,
                     (__force snd_pcm_state_t)f_flags);
 }
 
 /*
  * drain ioctl
  */
 
 /* drain init callbacks: state argument ignored */
 static int snd_pcm_pre_drain_init(struct snd_pcm_substream *substream,
                   snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     switch (runtime->status->state) {
     case SNDRV_PCM_STATE_OPEN:
     case SNDRV_PCM_STATE_DISCONNECTED:
     case SNDRV_PCM_STATE_SUSPENDED:
         return -EBADFD;
     }
     runtime->trigger_master = substream;
     return 0;
 }
 
 static int snd_pcm_do_drain_init(struct snd_pcm_substream *substream,
                  snd_pcm_state_t state)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
         switch (runtime->status->state) {
         case SNDRV_PCM_STATE_PREPARED:
             /* start playback stream if possible */
             if (! snd_pcm_playback_empty(substream)) {
                 snd_pcm_do_start(substream, SNDRV_PCM_STATE_DRAINING);
                 snd_pcm_post_start(substream, SNDRV_PCM_STATE_DRAINING);
             } else {
                 runtime->status->state = SNDRV_PCM_STATE_SETUP;
             }
             break;
         case SNDRV_PCM_STATE_RUNNING:
             runtime->status->state = SNDRV_PCM_STATE_DRAINING;
             break;
         case SNDRV_PCM_STATE_XRUN:
             runtime->status->state = SNDRV_PCM_STATE_SETUP;
             break;
         default:
             break;
         }
     } else {
         /* stop running stream */
         if (runtime->status->state == SNDRV_PCM_STATE_RUNNING) {
             snd_pcm_state_t new_state;
 
             new_state = snd_pcm_capture_avail(runtime) > 0 ?
                 SNDRV_PCM_STATE_DRAINING : SNDRV_PCM_STATE_SETUP;
             snd_pcm_do_stop(substream, new_state);
             snd_pcm_post_stop(substream, new_state);
         }
     }
 
     if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
         runtime->trigger_master == substream &&
         (runtime->hw.info & SNDRV_PCM_INFO_DRAIN_TRIGGER))
         return substream->ops->trigger(substream,
                            SNDRV_PCM_TRIGGER_DRAIN);
 
     return 0;
 }
 
 static void snd_pcm_post_drain_init(struct snd_pcm_substream *substream,
                     snd_pcm_state_t state)
 {
 }
 
 static const struct action_ops snd_pcm_action_drain_init = {
     .pre_action = snd_pcm_pre_drain_init,
     .do_action = snd_pcm_do_drain_init,
     .post_action = snd_pcm_post_drain_init
 };
 
 /*
  * Drain the stream(s).
  * When the substream is linked, sync until the draining of all playback streams
  * is finished.
  * After this call, all streams are supposed to be either SETUP or DRAINING
  * (capture only) state.
  */
 static int snd_pcm_drain(struct snd_pcm_substream *substream,
              struct file *file)
 {
     struct snd_card *card;
     struct snd_pcm_runtime *runtime;
     struct snd_pcm_substream *s;
     struct snd_pcm_group *group;
     wait_queue_entry_t wait;
     int result = 0;
     int nonblock = 0;
 
     card = substream->pcm->card;
     runtime = substream->runtime;
 
     if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
         return -EBADFD;
 
     if (file) {
         if (file->f_flags & O_NONBLOCK)
             nonblock = 1;
     } else if (substream->f_flags & O_NONBLOCK)
         nonblock = 1;
 
     snd_pcm_stream_lock_irq(substream);
     /* resume pause */
     if (runtime->status->state == SNDRV_PCM_STATE_PAUSED)
         snd_pcm_pause(substream, false);
 
     /* pre-start/stop - all running streams are changed to DRAINING state */
     result = snd_pcm_action(&snd_pcm_action_drain_init, substream,
                 ACTION_ARG_IGNORE);
     if (result < 0)
         goto unlock;
     /* in non-blocking, we don't wait in ioctl but let caller poll */
     if (nonblock) {
         result = -EAGAIN;
         goto unlock;
     }
 
     for (;;) {
         long tout;
         struct snd_pcm_runtime *to_check;
         if (signal_pending(current)) {
             result = -ERESTARTSYS;
             break;
         }
         /* find a substream to drain */
         to_check = NULL;
         group = snd_pcm_stream_group_ref(substream);
         snd_pcm_group_for_each_entry(s, substream) {
             if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
                 continue;
             runtime = s->runtime;
             if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
                 to_check = runtime;
                 break;
             }
         }
         snd_pcm_group_unref(group, substream);
         if (!to_check)
             break; /* all drained */
         init_waitqueue_entry(&wait, current);
         set_current_state(TASK_INTERRUPTIBLE);
         add_wait_queue(&to_check->sleep, &wait);
         snd_pcm_stream_unlock_irq(substream);
         if (runtime->no_period_wakeup)
             tout = MAX_SCHEDULE_TIMEOUT;
         else {
             tout = 10;
             if (runtime->rate) {
                 long t = runtime->period_size * 2 / runtime->rate;
                 tout = max(t, tout);
             }
             tout = msecs_to_jiffies(tout * 1000);
         }
         tout = schedule_timeout(tout);
 
         snd_pcm_stream_lock_irq(substream);
         group = snd_pcm_stream_group_ref(substream);
         snd_pcm_group_for_each_entry(s, substream) {
             if (s->runtime == to_check) {
                 remove_wait_queue(&to_check->sleep, &wait);
                 break;
             }
         }
         snd_pcm_group_unref(group, substream);
 
         if (card->shutdown) {
             result = -ENODEV;
             break;
         }
         if (tout == 0) {
             if (substream->runtime->status->state == SNDRV_PCM_STATE_SUSPENDED)
                 result = -ESTRPIPE;
             else {
                 dev_dbg(substream->pcm->card->dev,
                     "playback drain error (DMA or IRQ trouble?)\n");
                 snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
                 result = -EIO;
             }
             break;
         }
     }
 
  unlock:
     snd_pcm_stream_unlock_irq(substream);
 
     return result;
 }
 
 /*
  * drop ioctl
  *
  * Immediately put all linked substreams into SETUP state.
  */
 static int snd_pcm_drop(struct snd_pcm_substream *substream)
 {
     struct snd_pcm_runtime *runtime;
     int result = 0;
     
     if (PCM_RUNTIME_CHECK(substream))
         return -ENXIO;
     runtime = substream->runtime;
 
     if (runtime->status->state == SNDRV_PCM_STATE_OPEN ||
         runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
         return -EBADFD;
 
     snd_pcm_stream_lock_irq(substream);
     /* resume pause */
     if (runtime->status->state == SNDRV_PCM_STATE_PAUSED)
         snd_pcm_pause(substream, false);
 
     snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
     /* runtime->control->appl_ptr = runtime->status->hw_ptr; */
     snd_pcm_stream_unlock_irq(substream);
 
     return result;
 }
 
 
 static bool is_pcm_file(struct file *file)
 {
     struct inode *inode = file_inode(file);
     struct snd_pcm *pcm;
     unsigned int minor;
 
     if (!S_ISCHR(inode->i_mode) || imajor(inode) != snd_major)
         return false;
     minor = iminor(inode);
     pcm = snd_lookup_minor_data(minor, SNDRV_DEVICE_TYPE_PCM_PLAYBACK);
     if (!pcm)
         pcm = snd_lookup_minor_data(minor, SNDRV_DEVICE_TYPE_PCM_CAPTURE);
     if (!pcm)
         return false;
     snd_card_unref(pcm->card);
     return true;
 }
 
 /*
  * PCM link handling
  */
 static int snd_pcm_link(struct snd_pcm_substream *substream, int fd)
 {
     int res = 0;
     struct snd_pcm_file *pcm_file;
     struct snd_pcm_substream *substream1;
     struct snd_pcm_group *group, *target_group;
     bool nonatomic = substream->pcm->nonatomic;
     struct fd f = fdget(fd);
 
     if (!f.file)
         return -EBADFD;
     if (!is_pcm_file(f.file)) {
         res = -EBADFD;
         goto _badf;
     }
     pcm_file = f.file->private_data;
     substream1 = pcm_file->substream;
 
     if (substream == substream1) {
         res = -EINVAL;
         goto _badf;
     }
 
     group = kzalloc(sizeof(*group), GFP_KERNEL);
     if (!group) {
         res = -ENOMEM;
         goto _nolock;
     }
     snd_pcm_group_init(group);
 
     down_write(&snd_pcm_link_rwsem);
     if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN ||
         substream->runtime->status->state != substream1->runtime->status->state ||
         substream->pcm->nonatomic != substream1->pcm->nonatomic) {
         res = -EBADFD;
         goto _end;
     }
     if (snd_pcm_stream_linked(substream1)) {
         res = -EALREADY;
         goto _end;
     }
 
     snd_pcm_stream_lock_irq(substream);
     if (!snd_pcm_stream_linked(substream)) {
         snd_pcm_group_assign(substream, group);
         group = NULL; /* assigned, don't free this one below */
     }
     target_group = substream->group;
     snd_pcm_stream_unlock_irq(substream);
 
     snd_pcm_group_lock_irq(target_group, nonatomic);
     snd_pcm_stream_lock_nested(substream1);
     snd_pcm_group_assign(substream1, target_group);
     refcount_inc(&target_group->refs);
     snd_pcm_stream_unlock(substream1);
     snd_pcm_group_unlock_irq(target_group, nonatomic);
  _end:
     up_write(&snd_pcm_link_rwsem);
  _nolock:
     kfree(group);
  _badf:
     fdput(f);
     return res;
 }
 
 static void relink_to_local(struct snd_pcm_substream *substream)
 {
     snd_pcm_stream_lock_nested(substream);
     snd_pcm_group_assign(substream, &substream->self_group);
     snd_pcm_stream_unlock(substream);
 }
 
 static int snd_pcm_unlink(struct snd_pcm_substream *substream)
 {
     struct snd_pcm_group *group;
     bool nonatomic = substream->pcm->nonatomic;
     bool do_free = false;
     int res = 0;
 
     down_write(&snd_pcm_link_rwsem);
 
     if (!snd_pcm_stream_linked(substream)) {
         res = -EALREADY;
         goto _end;
     }
 
     group = substream->group;
     snd_pcm_group_lock_irq(group, nonatomic);
 
     relink_to_local(substream);
     refcount_dec(&group->refs);
 
     /* detach the last stream, too */
     if (list_is_singular(&group->substreams)) {
         relink_to_local(list_first_entry(&group->substreams,
                          struct snd_pcm_substream,
                          link_list));
         do_free = refcount_dec_and_test(&group->refs);
     }
 
     snd_pcm_group_unlock_irq(group, nonatomic);
     if (do_free)
         kfree(group);
 
        _end:
     up_write(&snd_pcm_link_rwsem);
     return res;
 }
 
 /*
  * hw configurator
  */
 static int snd_pcm_hw_rule_mul(struct snd_pcm_hw_params *params,
                    struct snd_pcm_hw_rule *rule)
 {
     struct snd_interval t;
     snd_interval_mul(hw_param_interval_c(params, rule->deps[0]),
              hw_param_interval_c(params, rule->deps[1]), &t);
     return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 }
 
 static int snd_pcm_hw_rule_div(struct snd_pcm_hw_params *params,
                    struct snd_pcm_hw_rule *rule)
 {
     struct snd_interval t;
     snd_interval_div(hw_param_interval_c(params, rule->deps[0]),
              hw_param_interval_c(params, rule->deps[1]), &t);
     return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 }
 
 static int snd_pcm_hw_rule_muldivk(struct snd_pcm_hw_params *params,
                    struct snd_pcm_hw_rule *rule)
 {
     struct snd_interval t;
     snd_interval_muldivk(hw_param_interval_c(params, rule->deps[0]),
              hw_param_interval_c(params, rule->deps[1]),
              (unsigned long) rule->private, &t);
     return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 }
 
 static int snd_pcm_hw_rule_mulkdiv(struct snd_pcm_hw_params *params,
                    struct snd_pcm_hw_rule *rule)
 {
     struct snd_interval t;
     snd_interval_mulkdiv(hw_param_interval_c(params, rule->deps[0]),
              (unsigned long) rule->private,
              hw_param_interval_c(params, rule->deps[1]), &t);
     return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 }
 
 static int snd_pcm_hw_rule_format(struct snd_pcm_hw_params *params,
                   struct snd_pcm_hw_rule *rule)
 {
     snd_pcm_format_t k;
     const struct snd_interval *i =
                 hw_param_interval_c(params, rule->deps[0]);
     struct snd_mask m;
     struct snd_mask *mask = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
     snd_mask_any(&m);
     pcm_for_each_format(k) {
         int bits;
         if (!snd_mask_test_format(mask, k))
             continue;
         bits = snd_pcm_format_physical_width(k);
         if (bits <= 0)
             continue; /* ignore invalid formats */
         if ((unsigned)bits < i->min || (unsigned)bits > i->max)
             snd_mask_reset(&m, (__force unsigned)k);
     }
     return snd_mask_refine(mask, &m);
 }
 
 static int snd_pcm_hw_rule_sample_bits(struct snd_pcm_hw_params *params,
                        struct snd_pcm_hw_rule *rule)
 {
     struct snd_interval t;
     snd_pcm_format_t k;
 
     t.min = UINT_MAX;
     t.max = 0;
     t.openmin = 0;
     t.openmax = 0;
     pcm_for_each_format(k) {
         int bits;
         if (!snd_mask_test_format(hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT), k))
             continue;
         bits = snd_pcm_format_physical_width(k);
         if (bits <= 0)
             continue; /* ignore invalid formats */
         if (t.min > (unsigned)bits)
             t.min = bits;
         if (t.max < (unsigned)bits)
             t.max = bits;
     }
     t.integer = 1;
     return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 }
 
 #if SNDRV_PCM_RATE_5512 != 1 << 0 || SNDRV_PCM_RATE_192000 != 1 << 12
 #error "Change this table"
 #endif
 
 static const unsigned int rates[] = {
     5512, 8000, 11025, 16000, 22050, 32000, 44100,
     48000, 64000, 88200, 96000, 176400, 192000, 352800, 384000
 };
 
 const struct snd_pcm_hw_constraint_list snd_pcm_known_rates = {
     .count = ARRAY_SIZE(rates),
     .list = rates,
 };
 
 static int snd_pcm_hw_rule_rate(struct snd_pcm_hw_params *params,
                 struct snd_pcm_hw_rule *rule)
 {
     struct snd_pcm_hardware *hw = rule->private;
     return snd_interval_list(hw_param_interval(params, rule->var),
                  snd_pcm_known_rates.count,
                  snd_pcm_known_rates.list, hw->rates);
 }       
 
 static int snd_pcm_hw_rule_buffer_bytes_max(struct snd_pcm_hw_params *params,
                         struct snd_pcm_hw_rule *rule)
 {
     struct snd_interval t;
     struct snd_pcm_substream *substream = rule->private;
     t.min = 0;
     t.max = substream->buffer_bytes_max;
     t.openmin = 0;
     t.openmax = 0;
     t.integer = 1;
     return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 }       
 
 static int snd_pcm_hw_constraints_init(struct snd_pcm_substream *substream)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
     int k, err;
 
     for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++) {
         snd_mask_any(constrs_mask(constrs, k));
     }
 
     for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++) {
         snd_interval_any(constrs_interval(constrs, k));
     }
 
     snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_CHANNELS));
     snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_BUFFER_SIZE));
     snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_BUFFER_BYTES));
     snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_SAMPLE_BITS));
     snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_FRAME_BITS));
 
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
                    snd_pcm_hw_rule_format, NULL,
                    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_SAMPLE_BITS, 
                   snd_pcm_hw_rule_sample_bits, NULL,
                   SNDRV_PCM_HW_PARAM_FORMAT, 
                   SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_SAMPLE_BITS, 
                   snd_pcm_hw_rule_div, NULL,
                   SNDRV_PCM_HW_PARAM_FRAME_BITS, SNDRV_PCM_HW_PARAM_CHANNELS, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FRAME_BITS, 
                   snd_pcm_hw_rule_mul, NULL,
                   SNDRV_PCM_HW_PARAM_SAMPLE_BITS, SNDRV_PCM_HW_PARAM_CHANNELS, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FRAME_BITS, 
                   snd_pcm_hw_rule_mulkdiv, (void*) 8,
                   SNDRV_PCM_HW_PARAM_PERIOD_BYTES, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FRAME_BITS, 
                   snd_pcm_hw_rule_mulkdiv, (void*) 8,
                   SNDRV_PCM_HW_PARAM_BUFFER_BYTES, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS, 
                   snd_pcm_hw_rule_div, NULL,
                   SNDRV_PCM_HW_PARAM_FRAME_BITS, SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, 
                   snd_pcm_hw_rule_mulkdiv, (void*) 1000000,
                   SNDRV_PCM_HW_PARAM_PERIOD_SIZE, SNDRV_PCM_HW_PARAM_PERIOD_TIME, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, 
                   snd_pcm_hw_rule_mulkdiv, (void*) 1000000,
                   SNDRV_PCM_HW_PARAM_BUFFER_SIZE, SNDRV_PCM_HW_PARAM_BUFFER_TIME, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIODS, 
                   snd_pcm_hw_rule_div, NULL,
                   SNDRV_PCM_HW_PARAM_BUFFER_SIZE, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 
                   snd_pcm_hw_rule_div, NULL,
                   SNDRV_PCM_HW_PARAM_BUFFER_SIZE, SNDRV_PCM_HW_PARAM_PERIODS, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 
                   snd_pcm_hw_rule_mulkdiv, (void*) 8,
                   SNDRV_PCM_HW_PARAM_PERIOD_BYTES, SNDRV_PCM_HW_PARAM_FRAME_BITS, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 
                   snd_pcm_hw_rule_muldivk, (void*) 1000000,
                   SNDRV_PCM_HW_PARAM_PERIOD_TIME, SNDRV_PCM_HW_PARAM_RATE, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 
                   snd_pcm_hw_rule_mul, NULL,
                   SNDRV_PCM_HW_PARAM_PERIOD_SIZE, SNDRV_PCM_HW_PARAM_PERIODS, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 
                   snd_pcm_hw_rule_mulkdiv, (void*) 8,
                   SNDRV_PCM_HW_PARAM_BUFFER_BYTES, SNDRV_PCM_HW_PARAM_FRAME_BITS, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 
                   snd_pcm_hw_rule_muldivk, (void*) 1000000,
                   SNDRV_PCM_HW_PARAM_BUFFER_TIME, SNDRV_PCM_HW_PARAM_RATE, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 
                   snd_pcm_hw_rule_muldivk, (void*) 8,
                   SNDRV_PCM_HW_PARAM_PERIOD_SIZE, SNDRV_PCM_HW_PARAM_FRAME_BITS, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 
                   snd_pcm_hw_rule_muldivk, (void*) 8,
                   SNDRV_PCM_HW_PARAM_BUFFER_SIZE, SNDRV_PCM_HW_PARAM_FRAME_BITS, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_TIME, 
                   snd_pcm_hw_rule_mulkdiv, (void*) 1000000,
                   SNDRV_PCM_HW_PARAM_PERIOD_SIZE, SNDRV_PCM_HW_PARAM_RATE, -1);
     if (err < 0)
         return err;
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_TIME, 
                   snd_pcm_hw_rule_mulkdiv, (void*) 1000000,
                   SNDRV_PCM_HW_PARAM_BUFFER_SIZE, SNDRV_PCM_HW_PARAM_RATE, -1);
     if (err < 0)
         return err;
     return 0;
 }
 
 static int snd_pcm_hw_constraints_complete(struct snd_pcm_substream *substream)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     struct snd_pcm_hardware *hw = &runtime->hw;
     int err;
     unsigned int mask = 0;
 
         if (hw->info & SNDRV_PCM_INFO_INTERLEAVED)
         mask |= PARAM_MASK_BIT(SNDRV_PCM_ACCESS_RW_INTERLEAVED);
         if (hw->info & SNDRV_PCM_INFO_NONINTERLEAVED)
         mask |= PARAM_MASK_BIT(SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
     if (hw_support_mmap(substream)) {
         if (hw->info & SNDRV_PCM_INFO_INTERLEAVED)
             mask |= PARAM_MASK_BIT(SNDRV_PCM_ACCESS_MMAP_INTERLEAVED);
         if (hw->info & SNDRV_PCM_INFO_NONINTERLEAVED)
             mask |= PARAM_MASK_BIT(SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED);
         if (hw->info & SNDRV_PCM_INFO_COMPLEX)
             mask |= PARAM_MASK_BIT(SNDRV_PCM_ACCESS_MMAP_COMPLEX);
     }
     err = snd_pcm_hw_constraint_mask(runtime, SNDRV_PCM_HW_PARAM_ACCESS, mask);
     if (err < 0)
         return err;
 
     err = snd_pcm_hw_constraint_mask64(runtime, SNDRV_PCM_HW_PARAM_FORMAT, hw->formats);
     if (err < 0)
         return err;
 
     err = snd_pcm_hw_constraint_mask(runtime, SNDRV_PCM_HW_PARAM_SUBFORMAT,
                      PARAM_MASK_BIT(SNDRV_PCM_SUBFORMAT_STD));
     if (err < 0)
         return err;
 
     err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_CHANNELS,
                        hw->channels_min, hw->channels_max);
     if (err < 0)
         return err;
 
     err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_RATE,
                        hw->rate_min, hw->rate_max);
     if (err < 0)
         return err;
 
     err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
                        hw->period_bytes_min, hw->period_bytes_max);
     if (err < 0)
         return err;
 
     err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIODS,
                        hw->periods_min, hw->periods_max);
     if (err < 0)
         return err;
 
     err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
                        hw->period_bytes_min, hw->buffer_bytes_max);
     if (err < 0)
         return err;
 
     err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 
                   snd_pcm_hw_rule_buffer_bytes_max, substream,
                   SNDRV_PCM_HW_PARAM_BUFFER_BYTES, -1);
     if (err < 0)
         return err;
 
     /* FIXME: remove */
     if (runtime->dma_bytes) {
         err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 0, runtime->dma_bytes);
         if (err < 0)
             return err;
     }
 
     if (!(hw->rates & (SNDRV_PCM_RATE_KNOT | SNDRV_PCM_RATE_CONTINUOUS))) {
         err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, 
                       snd_pcm_hw_rule_rate, hw,
                       SNDRV_PCM_HW_PARAM_RATE, -1);
         if (err < 0)
             return err;
     }
 
     /* FIXME: this belong to lowlevel */
     snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
 
     return 0;
 }
 
 static void pcm_release_private(struct snd_pcm_substream *substream)
 {
     if (snd_pcm_stream_linked(substream))
         snd_pcm_unlink(substream);
 }
 
 void snd_pcm_release_substream(struct snd_pcm_substream *substream)
 {
     substream->ref_count--;
     if (substream->ref_count > 0)
         return;
 
     snd_pcm_drop(substream);
     if (substream->hw_opened) {
         if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
             do_hw_free(substream);
         substream->ops->close(substream);
         substream->hw_opened = 0;
     }
     if (cpu_latency_qos_request_active(&substream->latency_pm_qos_req))
         cpu_latency_qos_remove_request(&substream->latency_pm_qos_req);
     if (substream->pcm_release) {
         substream->pcm_release(substream);
         substream->pcm_release = NULL;
     }
     snd_pcm_detach_substream(substream);
 }
 EXPORT_SYMBOL(snd_pcm_release_substream);
 
 int snd_pcm_open_substream(struct snd_pcm *pcm, int stream,
                struct file *file,
                struct snd_pcm_substream **rsubstream)
 {
     struct snd_pcm_substream *substream;
     int err;
 
     err = snd_pcm_attach_substream(pcm, stream, file, &substream);
     if (err < 0)
         return err;
     if (substream->ref_count > 1) {
         *rsubstream = substream;
         return 0;
     }
 
     err = snd_pcm_hw_constraints_init(substream);
     if (err < 0) {
         pcm_dbg(pcm, "snd_pcm_hw_constraints_init failed\n");
         goto error;
     }
 
     err = substream->ops->open(substream);
     if (err < 0)
         goto error;
 
     substream->hw_opened = 1;
 
     err = snd_pcm_hw_constraints_complete(substream);
     if (err < 0) {
         pcm_dbg(pcm, "snd_pcm_hw_constraints_complete failed\n");
         goto error;
     }
 
     /* automatically set EXPLICIT_SYNC flag in the managed mode whenever
      * the DMA buffer requires it
      */
     if (substream->managed_buffer_alloc &&
         substream->dma_buffer.dev.need_sync)
         substream->runtime->hw.info |= SNDRV_PCM_INFO_EXPLICIT_SYNC;
 
     *rsubstream = substream;
     return 0;
 
  error:
     snd_pcm_release_substream(substream);
     return err;
 }
 EXPORT_SYMBOL(snd_pcm_open_substream);
 
 static int snd_pcm_open_file(struct file *file,
                  struct snd_pcm *pcm,
                  int stream)
 {
     struct snd_pcm_file *pcm_file;
     struct snd_pcm_substream *substream;
     int err;
 
     err = snd_pcm_open_substream(pcm, stream, file, &substream);
     if (err < 0)
         return err;
 
     pcm_file = kzalloc(sizeof(*pcm_file), GFP_KERNEL);
     if (pcm_file == NULL) {
         snd_pcm_release_substream(substream);
         return -ENOMEM;
     }
     pcm_file->substream = substream;
     if (substream->ref_count == 1)
         substream->pcm_release = pcm_release_private;
     file->private_data = pcm_file;
 
     return 0;
 }
 
 static int snd_pcm_playback_open(struct inode *inode, struct file *file)
 {
     struct snd_pcm *pcm;
     int err = nonseekable_open(inode, file);
     if (err < 0)
         return err;
     pcm = snd_lookup_minor_data(iminor(inode),
                     SNDRV_DEVICE_TYPE_PCM_PLAYBACK);
     err = snd_pcm_open(file, pcm, SNDRV_PCM_STREAM_PLAYBACK);
     if (pcm)
         snd_card_unref(pcm->card);
     return err;
 }
 
 static int snd_pcm_capture_open(struct inode *inode, struct file *file)
 {
     struct snd_pcm *pcm;
     int err = nonseekable_open(inode, file);
     if (err < 0)
         return err;
     pcm = snd_lookup_minor_data(iminor(inode),
                     SNDRV_DEVICE_TYPE_PCM_CAPTURE);
     err = snd_pcm_open(file, pcm, SNDRV_PCM_STREAM_CAPTURE);
     if (pcm)
         snd_card_unref(pcm->card);
     return err;
 }
 
 static int snd_pcm_open(struct file *file, struct snd_pcm *pcm, int stream)
 {
     int err;
     wait_queue_entry_t wait;
 
     if (pcm == NULL) {
         err = -ENODEV;
         goto __error1;
     }
     err = snd_card_file_add(pcm->card, file);
     if (err < 0)
         goto __error1;
     if (!try_module_get(pcm->card->module)) {
         err = -EFAULT;
         goto __error2;
     }
     init_waitqueue_entry(&wait, current);
     add_wait_queue(&pcm->open_wait, &wait);
     mutex_lock(&pcm->open_mutex);
     while (1) {
         err = snd_pcm_open_file(file, pcm, stream);
         if (err >= 0)
             break;
         if (err == -EAGAIN) {
             if (file->f_flags & O_NONBLOCK) {
                 err = -EBUSY;
                 break;
             }
         } else
             break;
         set_current_state(TASK_INTERRUPTIBLE);
         mutex_unlock(&pcm->open_mutex);
         schedule();
         mutex_lock(&pcm->open_mutex);
         if (pcm->card->shutdown) {
             err = -ENODEV;
             break;
         }
         if (signal_pending(current)) {
             err = -ERESTARTSYS;
             break;
         }
     }
     remove_wait_queue(&pcm->open_wait, &wait);
     mutex_unlock(&pcm->open_mutex);
     if (err < 0)
         goto __error;
     return err;
 
       __error:
     module_put(pcm->card->module);
       __error2:
         snd_card_file_remove(pcm->card, file);
       __error1:
         return err;
 }
 
 static int snd_pcm_release(struct inode *inode, struct file *file)
 {
     struct snd_pcm *pcm;
     struct snd_pcm_substream *substream;
     struct snd_pcm_file *pcm_file;
 
     pcm_file = file->private_data;
     substream = pcm_file->substream;
     if (snd_BUG_ON(!substream))
         return -ENXIO;
     pcm = substream->pcm;
 
     /* block until the device gets woken up as it may touch the hardware */
     snd_power_wait(pcm->card);
 
     mutex_lock(&pcm->open_mutex);
     snd_pcm_release_substream(substream);
     kfree(pcm_file);
     mutex_unlock(&pcm->open_mutex);
     wake_up(&pcm->open_wait);
     module_put(pcm->card->module);
     snd_card_file_remove(pcm->card, file);
     return 0;
 }
 
 /* check and update PCM state; return 0 or a negative error
  * call this inside PCM lock
  */
 static int do_pcm_hwsync(struct snd_pcm_substream *substream)
 {
     switch (substream->runtime->status->state) {
     case SNDRV_PCM_STATE_DRAINING:
         if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
             return -EBADFD;
         fallthrough;
     case SNDRV_PCM_STATE_RUNNING:
         return snd_pcm_update_hw_ptr(substream);
     case SNDRV_PCM_STATE_PREPARED:
     case SNDRV_PCM_STATE_PAUSED:
         return 0;
     case SNDRV_PCM_STATE_SUSPENDED:
         return -ESTRPIPE;
     case SNDRV_PCM_STATE_XRUN:
         return -EPIPE;
     default:
         return -EBADFD;
     }
 }
 
 /* increase the appl_ptr; returns the processed frames or a negative error */
 static snd_pcm_sframes_t forward_appl_ptr(struct snd_pcm_substream *substream,
                       snd_pcm_uframes_t frames,
                        snd_pcm_sframes_t avail)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     snd_pcm_sframes_t appl_ptr;
     int ret;
 
     if (avail <= 0)
         return 0;
     if (frames > (snd_pcm_uframes_t)avail)
         frames = avail;
     appl_ptr = runtime->control->appl_ptr + frames;
     if (appl_ptr >= (snd_pcm_sframes_t)runtime->boundary)
         appl_ptr -= runtime->boundary;
     ret = pcm_lib_apply_appl_ptr(substream, appl_ptr);
     return ret < 0 ? ret : frames;
 }
 
 /* decrease the appl_ptr; returns the processed frames or zero for error */
 static snd_pcm_sframes_t rewind_appl_ptr(struct snd_pcm_substream *substream,
                      snd_pcm_uframes_t frames,
                      snd_pcm_sframes_t avail)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     snd_pcm_sframes_t appl_ptr;
     int ret;
 
     if (avail <= 0)
         return 0;
     if (frames > (snd_pcm_uframes_t)avail)
         frames = avail;
     appl_ptr = runtime->control->appl_ptr - frames;
     if (appl_ptr < 0)
         appl_ptr += runtime->boundary;
     ret = pcm_lib_apply_appl_ptr(substream, appl_ptr);
     /* NOTE: we return zero for errors because PulseAudio gets depressed
      * upon receiving an error from rewind ioctl and stops processing
      * any longer.  Returning zero means that no rewind is done, so
      * it's not absolutely wrong to answer like that.
      */
     return ret < 0 ? 0 : frames;
 }
 
 static snd_pcm_sframes_t snd_pcm_rewind(struct snd_pcm_substream *substream,
                     snd_pcm_uframes_t frames)
 {
     snd_pcm_sframes_t ret;
 
     if (frames == 0)
         return 0;
 
     snd_pcm_stream_lock_irq(substream);
     ret = do_pcm_hwsync(substream);
     if (!ret)
         ret = rewind_appl_ptr(substream, frames,
                       snd_pcm_hw_avail(substream));
     snd_pcm_stream_unlock_irq(substream);
     if (ret >= 0)
         snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
     return ret;
 }
 
 static snd_pcm_sframes_t snd_pcm_forward(struct snd_pcm_substream *substream,
                      snd_pcm_uframes_t frames)
 {
     snd_pcm_sframes_t ret;
 
     if (frames == 0)
         return 0;
 
     snd_pcm_stream_lock_irq(substream);
     ret = do_pcm_hwsync(substream);
     if (!ret)
         ret = forward_appl_ptr(substream, frames,
                        snd_pcm_avail(substream));
     snd_pcm_stream_unlock_irq(substream);
     if (ret >= 0)
         snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
     return ret;
 }
 
 static int snd_pcm_delay(struct snd_pcm_substream *substream,
              snd_pcm_sframes_t *delay)
 {
     int err;
 
     snd_pcm_stream_lock_irq(substream);
     err = do_pcm_hwsync(substream);
     if (delay && !err)
         *delay = snd_pcm_calc_delay(substream);
     snd_pcm_stream_unlock_irq(substream);
     snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_CPU);
 
     return err;
 }
         
 static inline int snd_pcm_hwsync(struct snd_pcm_substream *substream)
 {
     return snd_pcm_delay(substream, NULL);
 }
 
 static int snd_pcm_sync_ptr(struct snd_pcm_substream *substream,
                 struct snd_pcm_sync_ptr __user *_sync_ptr)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     struct snd_pcm_sync_ptr sync_ptr;
     volatile struct snd_pcm_mmap_status *status;
     volatile struct snd_pcm_mmap_control *control;
     int err;
 
     memset(&sync_ptr, 0, sizeof(sync_ptr));
     if (get_user(sync_ptr.flags, (unsigned __user *)&(_sync_ptr->flags)))
         return -EFAULT;
     if (copy_from_user(&sync_ptr.c.control, &(_sync_ptr->c.control), sizeof(struct snd_pcm_mmap_control)))
         return -EFAULT; 
     status = runtime->status;
     control = runtime->control;
     if (sync_ptr.flags & SNDRV_PCM_SYNC_PTR_HWSYNC) {
         err = snd_pcm_hwsync(substream);
         if (err < 0)
             return err;
     }
     snd_pcm_stream_lock_irq(substream);
     if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_APPL)) {
         err = pcm_lib_apply_appl_ptr(substream,
                          sync_ptr.c.control.appl_ptr);
         if (err < 0) {
             snd_pcm_stream_unlock_irq(substream);
             return err;
         }
     } else {
         sync_ptr.c.control.appl_ptr = control->appl_ptr;
     }
     if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_AVAIL_MIN))
         control->avail_min = sync_ptr.c.control.avail_min;
     else
         sync_ptr.c.control.avail_min = control->avail_min;
     sync_ptr.s.status.state = status->state;
     sync_ptr.s.status.hw_ptr = status->hw_ptr;
     sync_ptr.s.status.tstamp = status->tstamp;
     sync_ptr.s.status.suspended_state = status->suspended_state;
     sync_ptr.s.status.audio_tstamp = status->audio_tstamp;
     snd_pcm_stream_unlock_irq(substream);
     if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_APPL))
         snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
     if (copy_to_user(_sync_ptr, &sync_ptr, sizeof(sync_ptr)))
         return -EFAULT;
     return 0;
 }
 
 struct snd_pcm_mmap_status32 {
     snd_pcm_state_t state;
     s32 pad1;
     u32 hw_ptr;
     s32 tstamp_sec;
     s32 tstamp_nsec;
     snd_pcm_state_t suspended_state;
     s32 audio_tstamp_sec;
     s32 audio_tstamp_nsec;
 } __attribute__((packed));
 
 struct snd_pcm_mmap_control32 {
     u32 appl_ptr;
     u32 avail_min;
 };
 
 struct snd_pcm_sync_ptr32 {
     u32 flags;
     union {
         struct snd_pcm_mmap_status32 status;
         unsigned char reserved[64];
     } s;
     union {
         struct snd_pcm_mmap_control32 control;
         unsigned char reserved[64];
     } c;
 } __attribute__((packed));
 
 /* recalcuate the boundary within 32bit */
 static snd_pcm_uframes_t recalculate_boundary(struct snd_pcm_runtime *runtime)
 {
     snd_pcm_uframes_t boundary;
 
     if (! runtime->buffer_size)
         return 0;
     boundary = runtime->buffer_size;
     while (boundary * 2 <= 0x7fffffffUL - runtime->buffer_size)
         boundary *= 2;
     return boundary;
 }
 
 static int snd_pcm_ioctl_sync_ptr_compat(struct snd_pcm_substream *substream,
                      struct snd_pcm_sync_ptr32 __user *src)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     volatile struct snd_pcm_mmap_status *status;
     volatile struct snd_pcm_mmap_control *control;
     u32 sflags;
     struct snd_pcm_mmap_control scontrol;
     struct snd_pcm_mmap_status sstatus;
     snd_pcm_uframes_t boundary;
     int err;
 
     if (snd_BUG_ON(!runtime))
         return -EINVAL;
 
     if (get_user(sflags, &src->flags) ||
         get_user(scontrol.appl_ptr, &src->c.control.appl_ptr) ||
         get_user(scontrol.avail_min, &src->c.control.avail_min))
         return -EFAULT;
     if (sflags & SNDRV_PCM_SYNC_PTR_HWSYNC) {
         err = snd_pcm_hwsync(substream);
         if (err < 0)
             return err;
     }
     status = runtime->status;
     control = runtime->control;
     boundary = recalculate_boundary(runtime);
     if (! boundary)
         boundary = 0x7fffffff;
     snd_pcm_stream_lock_irq(substream);
     /* FIXME: we should consider the boundary for the sync from app */
     if (!(sflags & SNDRV_PCM_SYNC_PTR_APPL)) {
         err = pcm_lib_apply_appl_ptr(substream,
                 scontrol.appl_ptr);
         if (err < 0) {
             snd_pcm_stream_unlock_irq(substream);
             return err;
         }
     } else
         scontrol.appl_ptr = control->appl_ptr % boundary;
     if (!(sflags & SNDRV_PCM_SYNC_PTR_AVAIL_MIN))
         control->avail_min = scontrol.avail_min;
     else
         scontrol.avail_min = control->avail_min;
     sstatus.state = status->state;
     sstatus.hw_ptr = status->hw_ptr % boundary;
     sstatus.tstamp = status->tstamp;
     sstatus.suspended_state = status->suspended_state;
     sstatus.audio_tstamp = status->audio_tstamp;
     snd_pcm_stream_unlock_irq(substream);
     if (!(sflags & SNDRV_PCM_SYNC_PTR_APPL))
         snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
     if (put_user(sstatus.state, &src->s.status.state) ||
         put_user(sstatus.hw_ptr, &src->s.status.hw_ptr) ||
         put_user(sstatus.tstamp.tv_sec, &src->s.status.tstamp_sec) ||
         put_user(sstatus.tstamp.tv_nsec, &src->s.status.tstamp_nsec) ||
         put_user(sstatus.suspended_state, &src->s.status.suspended_state) ||
         put_user(sstatus.audio_tstamp.tv_sec, &src->s.status.audio_tstamp_sec) ||
         put_user(sstatus.audio_tstamp.tv_nsec, &src->s.status.audio_tstamp_nsec) ||
         put_user(scontrol.appl_ptr, &src->c.control.appl_ptr) ||
         put_user(scontrol.avail_min, &src->c.control.avail_min))
         return -EFAULT;
 
     return 0;
 }
 #define __SNDRV_PCM_IOCTL_SYNC_PTR32 _IOWR('A', 0x23, struct snd_pcm_sync_ptr32)
 
 static int snd_pcm_tstamp(struct snd_pcm_substream *substream, int __user *_arg)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
     int arg;
     
     if (get_user(arg, _arg))
         return -EFAULT;
     if (arg < 0 || arg > SNDRV_PCM_TSTAMP_TYPE_LAST)
         return -EINVAL;
     runtime->tstamp_type = arg;
     return 0;
 }
 
 static int snd_pcm_xferi_frames_ioctl(struct snd_pcm_substream *substream,
                       struct snd_xferi __user *_xferi)
 {
     struct snd_xferi xferi;
     struct snd_pcm_runtime *runtime = substream->runtime;
     snd_pcm_sframes_t result;
 
     if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
         return -EBADFD;
     if (put_user(0, &_xferi->result))
         return -EFAULT;
     if (copy_from_user(&xferi, _xferi, sizeof(xferi)))
         return -EFAULT;
     if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
         result = snd_pcm_lib_write(substream, xferi.buf, xferi.frames);
     else
         result = snd_pcm_lib_read(substream, xferi.buf, xferi.frames);
     if (put_user(result, &_xferi->result))
         return -EFAULT;
     return result < 0 ? result : 0;
 }
 
 static int snd_pcm_xfern_frames_ioctl(struct snd_pcm_substream *substream,
                       struct snd_xfern __user *_xfern)
 {
     struct snd_xfern xfern;
     struct snd_pcm_runtime *runtime = substream->runtime;
     void *bufs;
     snd_pcm_sframes_t result;
 
     if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
         return -EBADFD;
     if (runtime->channels > 128)
         return -EINVAL;
     if (put_user(0, &_xfern->result))
         return -EFAULT;
     if (copy_from_user(&xfern, _xfern, sizeof(xfern)))
         return -EFAULT;
 
     bufs = memdup_user(xfern.bufs, sizeof(void *) * runtime->channels);
     if (IS_ERR(bufs))
         return PTR_ERR(bufs);
     if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
         result = snd_pcm_lib_writev(substream, bufs, xfern.frames);
     else
         result = snd_pcm_lib_readv(substream, bufs, xfern.frames);
     kfree(bufs);
     if (put_user(result, &_xfern->result))
         return -EFAULT;
     return result < 0 ? result : 0;
 }
 
 static int snd_pcm_rewind_ioctl(struct snd_pcm_substream *substream,
                 snd_pcm_uframes_t __user *_frames)
 {
     snd_pcm_uframes_t frames;
     snd_pcm_sframes_t result;
 
     if (get_user(frames, _frames))
         return -EFAULT;
     if (put_user(0, _frames))
         return -EFAULT;
     result = snd_pcm_rewind(substream, frames);
     if (put_user(result, _frames))
         return -EFAULT;
     return result < 0 ? result : 0;
 }
 
 static int snd_pcm_forward_ioctl(struct snd_pcm_substream *substream,
                  snd_pcm_uframes_t __user *_frames)
 {
     snd_pcm_uframes_t frames;
     snd_pcm_sframes_t result;
 
     if (get_user(frames, _frames))
         return -EFAULT;
     if (put_user(0, _frames))
         return -EFAULT;
     result = snd_pcm_forward(substream, frames);
     if (put_user(result, _frames))
         return -EFAULT;
     return result < 0 ? result : 0;
 }
 
 static int snd_pcm_common_ioctl(struct file *file,
                  struct snd_pcm_substream *substream,
                  unsigned int cmd, void __user *arg)
 {
     struct snd_pcm_file *pcm_file = file->private_data;
     int res;
 
     if (PCM_RUNTIME_CHECK(substream))
         return -ENXIO;
 
     if (substream->runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
         return -EBADFD;
 
     res = snd_power_wait(substream->pcm->card);
     if (res < 0)
         return res;
 
     switch (cmd) {
     case SNDRV_PCM_IOCTL_PVERSION:
         return put_user(SNDRV_PCM_VERSION, (int __user *)arg) ? -EFAULT : 0;
     case SNDRV_PCM_IOCTL_INFO:
         return snd_pcm_info_user(substream, arg);
     case SNDRV_PCM_IOCTL_TSTAMP:    /* just for compatibility */
         return 0;
     case SNDRV_PCM_IOCTL_TTSTAMP:
         return snd_pcm_tstamp(substream, arg);
     case SNDRV_PCM_IOCTL_USER_PVERSION:
         if (get_user(pcm_file->user_pversion,
                  (unsigned int __user *)arg))
             return -EFAULT;
         return 0;
     case SNDRV_PCM_IOCTL_HW_REFINE:
         return snd_pcm_hw_refine_user(substream, arg);
     case SNDRV_PCM_IOCTL_HW_PARAMS:
         return snd_pcm_hw_params_user(substream, arg);
     case SNDRV_PCM_IOCTL_HW_FREE:
         return snd_pcm_hw_free(substream);
     case SNDRV_PCM_IOCTL_SW_PARAMS:
         return snd_pcm_sw_params_user(substream, arg);
     case SNDRV_PCM_IOCTL_STATUS32:
         return snd_pcm_status_user32(substream, arg, false);
     case SNDRV_PCM_IOCTL_STATUS_EXT32:
         return snd_pcm_status_user32(substream, arg, true);
     case SNDRV_PCM_IOCTL_STATUS64:
         return snd_pcm_status_user64(substream, arg, false);
     case SNDRV_PCM_IOCTL_STATUS_EXT64:
         return snd_pcm_status_user64(substream, arg, true);
     case SNDRV_PCM_IOCTL_CHANNEL_INFO:
         return snd_pcm_channel_info_user(substream, arg);
     case SNDRV_PCM_IOCTL_PREPARE:
         return snd_pcm_prepare(substream, file);
     case SNDRV_PCM_IOCTL_RESET:
         return snd_pcm_reset(substream);
     case SNDRV_PCM_IOCTL_START:
         return snd_pcm_start_lock_irq(substream);
     case SNDRV_PCM_IOCTL_LINK:
         return snd_pcm_link(substream, (int)(unsigned long) arg);
     case SNDRV_PCM_IOCTL_UNLINK:
         return snd_pcm_unlink(substream);
     case SNDRV_PCM_IOCTL_RESUME:
         return snd_pcm_resume(substream);
     case SNDRV_PCM_IOCTL_XRUN:
         return snd_pcm_xrun(substream);
     case SNDRV_PCM_IOCTL_HWSYNC:
         return snd_pcm_hwsync(substream);
     case SNDRV_PCM_IOCTL_DELAY:
     {
         snd_pcm_sframes_t delay = 0;
         snd_pcm_sframes_t __user *res = arg;
         int err;
 
         err = snd_pcm_delay(substream, &delay);
         if (err)
             return err;
         if (put_user(delay, res))
             return -EFAULT;
         return 0;
     }
     case __SNDRV_PCM_IOCTL_SYNC_PTR32:
         return snd_pcm_ioctl_sync_ptr_compat(substream, arg);
     case __SNDRV_PCM_IOCTL_SYNC_PTR64:
         return snd_pcm_sync_ptr(substream, arg);
 #ifdef CONFIG_SND_SUPPORT_OLD_API
     case SNDRV_PCM_IOCTL_HW_REFINE_OLD:
         return snd_pcm_hw_refine_old_user(substream, arg);
     case SNDRV_PCM_IOCTL_HW_PARAMS_OLD:
         return snd_pcm_hw_params_old_user(substream, arg);
 #endif
     case SNDRV_PCM_IOCTL_DRAIN:
         return snd_pcm_drain(substream, file);
     case SNDRV_PCM_IOCTL_DROP:
         return snd_pcm_drop(substream);
     case SNDRV_PCM_IOCTL_PAUSE:
         return snd_pcm_pause_lock_irq(substream, (unsigned long)arg);
     case SNDRV_PCM_IOCTL_WRITEI_FRAMES:
     case SNDRV_PCM_IOCTL_READI_FRAMES:
         return snd_pcm_xferi_frames_ioctl(substream, arg);
     case SNDRV_PCM_IOCTL_WRITEN_FRAMES:
     case SNDRV_PCM_IOCTL_READN_FRAMES:
         return snd_pcm_xfern_frames_ioctl(substream, arg);
     case SNDRV_PCM_IOCTL_REWIND:
         return snd_pcm_rewind_ioctl(substream, arg);
     case SNDRV_PCM_IOCTL_FORWARD:
         return snd_pcm_forward_ioctl(substream, arg);
     }
     pcm_dbg(substream->pcm, "unknown ioctl = 0x%x\n", cmd);
     return -ENOTTY;
 }
 
 static long snd_pcm_ioctl(struct file *file, unsigned int cmd,
               unsigned long arg)
 {
     struct snd_pcm_file *pcm_file;
 
     pcm_file = file->private_data;
 
     if (((cmd >> 8) & 0xff) != 'A')
         return -ENOTTY;
 
     return snd_pcm_common_ioctl(file, pcm_file->substream, cmd,
                      (void __user *)arg);
 }
 
 /**
  * snd_pcm_kernel_ioctl - Execute PCM ioctl in the kernel-space
  * @substream: PCM substream
  * @cmd: IOCTL cmd
  * @arg: IOCTL argument
  *
  * The function is provided primarily for OSS layer and USB gadget drivers,
  * and it allows only the limited set of ioctls (hw_params, sw_params,
  * prepare, start, drain, drop, forward).
  *
  * Return: zero if successful, or a negative error code
  */
 int snd_pcm_kernel_ioctl(struct snd_pcm_substream *substream,
              unsigned int cmd, void *arg)
 {
     snd_pcm_uframes_t *frames = arg;
     snd_pcm_sframes_t result;
     
     if (substream->runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
         return -EBADFD;
 
     switch (cmd) {
     case SNDRV_PCM_IOCTL_FORWARD:
     {
         /* provided only for OSS; capture-only and no value returned */
         if (substream->stream != SNDRV_PCM_STREAM_CAPTURE)
             return -EINVAL;
         result = snd_pcm_forward(substream, *frames);
         return result < 0 ? result : 0;
     }
     case SNDRV_PCM_IOCTL_HW_PARAMS:
         return snd_pcm_hw_params(substream, arg);
     case SNDRV_PCM_IOCTL_SW_PARAMS:
         return snd_pcm_sw_params(substream, arg);
     case SNDRV_PCM_IOCTL_PREPARE:
         return snd_pcm_prepare(substream, NULL);
     case SNDRV_PCM_IOCTL_START:
         return snd_pcm_start_lock_irq(substream);
     case SNDRV_PCM_IOCTL_DRAIN:
         return snd_pcm_drain(substream, NULL);
     case SNDRV_PCM_IOCTL_DROP:
         return snd_pcm_drop(substream);
     case SNDRV_PCM_IOCTL_DELAY:
         return snd_pcm_delay(substream, frames);
     default:
         return -EINVAL;
     }
 }
 EXPORT_SYMBOL(snd_pcm_kernel_ioctl);
 
 static ssize_t snd_pcm_read(struct file *file, char __user *buf, size_t count,
                 loff_t * offset)
 {
     struct snd_pcm_file *pcm_file;
     struct snd_pcm_substream *substream;
     struct snd_pcm_runtime *runtime;
     snd_pcm_sframes_t result;
 
     pcm_file = file->private_data;
     substream = pcm_file->substream;
     if (PCM_RUNTIME_CHECK(substream))
         return -ENXIO;
     runtime = substream->runtime;
     if (runtime->status->state == SNDRV_PCM_STATE_OPEN ||
         runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
         return -EBADFD;
     if (!frame_aligned(runtime, count))
         return -EINVAL;
     count = bytes_to_frames(runtime, count);
     result = snd_pcm_lib_read(substream, buf, count);
     if (result > 0)
         result = frames_to_bytes(runtime, result);
     return result;
 }
 
 static ssize_t snd_pcm_write(struct file *file, const char __user *buf,
                  size_t count, loff_t * offset)
 {
     struct snd_pcm_file *pcm_file;
     struct snd_pcm_substream *substream;
     struct snd_pcm_runtime *runtime;
     snd_pcm_sframes_t result;
 
     pcm_file = file->private_data;
     substream = pcm_file->substream;
     if (PCM_RUNTIME_CHECK(substream))
         return -ENXIO;
     runtime = substream->runtime;
     if (runtime->status->state == SNDRV_PCM_STATE_OPEN ||
         runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
         return -EBADFD;
     if (!frame_aligned(runtime, count))
         return -EINVAL;
     count = bytes_to_frames(runtime, count);
     result = snd_pcm_lib_write(substream, buf, count);
     if (result > 0)
         result = frames_to_bytes(runtime, result);
     return result;
 }
 
 static ssize_t snd_pcm_readv(struct kiocb *iocb, struct iov_iter *to)
 {
     struct snd_pcm_file *pcm_file;
     struct snd_pcm_substream *substream;
     struct snd_pcm_runtime *runtime;
     snd_pcm_sframes_t result;
     unsigned long i;
     void __user **bufs;
     snd_pcm_uframes_t frames;
 
     pcm_file = iocb->ki_filp->private_data;
     substream = pcm_file->substream;
     if (PCM_RUNTIME_CHECK(substream))
         return -ENXIO;
     runtime = substream->runtime;
     if (runtime->status->state == SNDRV_PCM_STATE_OPEN ||
         runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
         return -EBADFD;
     if (!iter_is_iovec(to))
         return -EINVAL;
     if (to->nr_segs > 1024 || to->nr_segs != runtime->channels)
         return -EINVAL;
     if (!frame_aligned(runtime, to->iov->iov_len))
         return -EINVAL;
     frames = bytes_to_samples(runtime, to->iov->iov_len);
     bufs = kmalloc_array(to->nr_segs, sizeof(void *), GFP_KERNEL);
     if (bufs == NULL)
         return -ENOMEM;
     for (i = 0; i < to->nr_segs; ++i)
         bufs[i] = to->iov[i].iov_base;
     result = snd_pcm_lib_readv(substream, bufs, frames);
     if (result > 0)
         result = frames_to_bytes(runtime, result);
     kfree(bufs);
     return result;
 }
 
 static ssize_t snd_pcm_writev(struct kiocb *iocb, struct iov_iter *from)
 {
     struct snd_pcm_file *pcm_file;
     struct snd_pcm_substream *substream;
     struct snd_pcm_runtime *runtime;
     snd_pcm_sframes_t result;
     unsigned long i;
     void __user **bufs;
     snd_pcm_uframes_t frames;
 
     pcm_file = iocb->ki_filp->private_data;
     substream = pcm_file->substream;
     if (PCM_RUNTIME_CHECK(substream))
         return -ENXIO;
     runtime = substream->runtime;
     if (runtime->status->state == SNDRV_PCM_STATE_OPEN ||
         runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
         return -EBADFD;
     if (!iter_is_iovec(from))
         return -EINVAL;
     if (from->nr_segs > 128 || from->nr_segs != runtime->channels ||
         !frame_aligned(runtime, from->iov->iov_len))
         return -EINVAL;
     frames = bytes_to_samples(runtime, from->iov->iov_len);
     bufs = kmalloc_array(from->nr_segs, sizeof(void *), GFP_KERNEL);
     if (bufs == NULL)
         return -ENOMEM;
     for (i = 0; i < from->nr_segs; ++i)
         bufs[i] = from->iov[i].iov_base;
     result = snd_pcm_lib_writev(substream, bufs, frames);
     if (result > 0)
         result = frames_to_bytes(runtime, result);
     kfree(bufs);
     return result;
 }
 
 static __poll_t snd_pcm_poll(struct file *file, poll_table *wait)
 {
     struct snd_pcm_file *pcm_file;
     struct snd_pcm_substream *substream;
     struct snd_pcm_runtime *runtime;
     __poll_t mask, ok;
     snd_pcm_uframes_t avail;
 
     pcm_file = file->private_data;
 
     substream = pcm_file->substream;
     if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
         ok = EPOLLOUT | EPOLLWRNORM;
     else
         ok = EPOLLIN | EPOLLRDNORM;
     if (PCM_RUNTIME_CHECK(substream))
         return ok | EPOLLERR;
 
     runtime = substream->runtime;
     if (runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
         return ok | EPOLLERR;
 
     poll_wait(file, &runtime->sleep, wait);
 
     mask = 0;
     snd_pcm_stream_lock_irq(substream);
     avail = snd_pcm_avail(substream);
     switch (runtime->status->state) {
     case SNDRV_PCM_STATE_RUNNING:
     case SNDRV_PCM_STATE_PREPARED:
     case SNDRV_PCM_STATE_PAUSED:
         if (avail >= runtime->control->avail_min)
             mask = ok;
         break;
     case SNDRV_PCM_STATE_DRAINING:
         if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
             mask = ok;
             if (!avail)
                 mask |= EPOLLERR;
         }
         break;
     default:
         mask = ok | EPOLLERR;
         break;
     }
     snd_pcm_stream_unlock_irq(substream);
     return mask;
 }
 
 /*
  * mmap support
  */
 
 /*
  * Only on coherent architectures, we can mmap the status and the control records
  * for effcient data transfer.  On others, we have to use HWSYNC ioctl...
  */
 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_ALPHA)
 /*
  * mmap status record
  */
 static vm_fault_t snd_pcm_mmap_status_fault(struct vm_fault *vmf)
 {
     struct snd_pcm_substream *substream = vmf->vma->vm_private_data;
     struct snd_pcm_runtime *runtime;
     
     if (substream == NULL)
         return VM_FAULT_SIGBUS;
     runtime = substream->runtime;
     vmf->page = virt_to_page(runtime->status);
     get_page(vmf->page);
     return 0;
 }
 
 static const struct vm_operations_struct snd_pcm_vm_ops_status =
 {
     .fault =    snd_pcm_mmap_status_fault,
 };
 
 static int snd_pcm_mmap_status(struct snd_pcm_substream *substream, struct file *file,
                    struct vm_area_struct *area)
 {
     long size;
     if (!(area->vm_flags & VM_READ))
         return -EINVAL;
     size = area->vm_end - area->vm_start;
     if (size != PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)))
         return -EINVAL;
     area->vm_ops = &snd_pcm_vm_ops_status;
     area->vm_private_data = substream;
     area->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
     return 0;
 }
 
 /*
  * mmap control record
  */
 static vm_fault_t snd_pcm_mmap_control_fault(struct vm_fault *vmf)
 {
     struct snd_pcm_substream *substream = vmf->vma->vm_private_data;
     struct snd_pcm_runtime *runtime;
     
     if (substream == NULL)
         return VM_FAULT_SIGBUS;
     runtime = substream->runtime;
     vmf->page = virt_to_page(runtime->control);
     get_page(vmf->page);
     return 0;
 }
 
 static const struct vm_operations_struct snd_pcm_vm_ops_control =
 {
     .fault =    snd_pcm_mmap_control_fault,
 };
 
 static int snd_pcm_mmap_control(struct snd_pcm_substream *substream, struct file *file,
                 struct vm_area_struct *area)
 {
     long size;
     if (!(area->vm_flags & VM_READ))
         return -EINVAL;
     size = area->vm_end - area->vm_start;
     if (size != PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)))
         return -EINVAL;
     area->vm_ops = &snd_pcm_vm_ops_control;
     area->vm_private_data = substream;
     area->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
     return 0;
 }
 
 static bool pcm_status_mmap_allowed(struct snd_pcm_file *pcm_file)
 {
     /* If drivers require the explicit sync (typically for non-coherent
      * pages), we have to disable the mmap of status and control data
      * to enforce the control via SYNC_PTR ioctl.
      */
     if (pcm_file->substream->runtime->hw.info & SNDRV_PCM_INFO_EXPLICIT_SYNC)
         return false;
     /* See pcm_control_mmap_allowed() below.
      * Since older alsa-lib requires both status and control mmaps to be
      * coupled, we have to disable the status mmap for old alsa-lib, too.
      */
     if (pcm_file->user_pversion < SNDRV_PROTOCOL_VERSION(2, 0, 14) &&
         (pcm_file->substream->runtime->hw.info & SNDRV_PCM_INFO_SYNC_APPLPTR))
         return false;
     return true;
 }
 
 static bool pcm_control_mmap_allowed(struct snd_pcm_file *pcm_file)
 {
     if (pcm_file->no_compat_mmap)
         return false;
     /* see above */
     if (pcm_file->substream->runtime->hw.info & SNDRV_PCM_INFO_EXPLICIT_SYNC)
         return false;
     /* Disallow the control mmap when SYNC_APPLPTR flag is set;
      * it enforces the user-space to fall back to snd_pcm_sync_ptr(),
      * thus it effectively assures the manual update of appl_ptr.
      */
     if (pcm_file->substream->runtime->hw.info & SNDRV_PCM_INFO_SYNC_APPLPTR)
         return false;
     return true;
 }
 
 #else /* ! coherent mmap */
 /*
  * don't support mmap for status and control records.
  */
 #define pcm_status_mmap_allowed(pcm_file)   false
 #define pcm_control_mmap_allowed(pcm_file)  false
 
 static int snd_pcm_mmap_status(struct snd_pcm_substream *substream, struct file *file,
                    struct vm_area_struct *area)
 {
     return -ENXIO;
 }
 static int snd_pcm_mmap_control(struct snd_pcm_substream *substream, struct file *file,
                 struct vm_area_struct *area)
 {
     return -ENXIO;
 }
 #endif /* coherent mmap */
 
 /*
  * fault callback for mmapping a RAM page
  */
 static vm_fault_t snd_pcm_mmap_data_fault(struct vm_fault *vmf)
 {
     struct snd_pcm_substream *substream = vmf->vma->vm_private_data;
     struct snd_pcm_runtime *runtime;
     unsigned long offset;
     struct page * page;
     size_t dma_bytes;
     
     if (substream == NULL)
         return VM_FAULT_SIGBUS;
     runtime = substream->runtime;
     offset = vmf->pgoff << PAGE_SHIFT;
     dma_bytes = PAGE_ALIGN(runtime->dma_bytes);
     if (offset > dma_bytes - PAGE_SIZE)
         return VM_FAULT_SIGBUS;
     if (substream->ops->page)
         page = substream->ops->page(substream, offset);
     else if (!snd_pcm_get_dma_buf(substream))
         page = virt_to_page(runtime->dma_area + offset);
     else
         page = snd_sgbuf_get_page(snd_pcm_get_dma_buf(substream), offset);
     if (!page)
         return VM_FAULT_SIGBUS;
     get_page(page);
     vmf->page = page;
     return 0;
 }
 
 static const struct vm_operations_struct snd_pcm_vm_ops_data = {
     .open =     snd_pcm_mmap_data_open,
     .close =    snd_pcm_mmap_data_close,
 };
 
 static const struct vm_operations_struct snd_pcm_vm_ops_data_fault = {
     .open =     snd_pcm_mmap_data_open,
     .close =    snd_pcm_mmap_data_close,
     .fault =    snd_pcm_mmap_data_fault,
 };
 
 /*
  * mmap the DMA buffer on RAM
  */
 
 /**
  * snd_pcm_lib_default_mmap - Default PCM data mmap function
  * @substream: PCM substream
  * @area: VMA
  *
  * This is the default mmap handler for PCM data.  When mmap pcm_ops is NULL,
  * this function is invoked implicitly.
  *
  * Return: zero if successful, or a negative error code
  */
 int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream,
                  struct vm_area_struct *area)
 {
     area->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
     if (!substream->ops->page &&
         !snd_dma_buffer_mmap(snd_pcm_get_dma_buf(substream), area))
         return 0;
     /* mmap with fault handler */
     area->vm_ops = &snd_pcm_vm_ops_data_fault;
     return 0;
 }
 EXPORT_SYMBOL_GPL(snd_pcm_lib_default_mmap);
 
 /*
  * mmap the DMA buffer on I/O memory area
  */
 #if SNDRV_PCM_INFO_MMAP_IOMEM
 /**
  * snd_pcm_lib_mmap_iomem - Default PCM data mmap function for I/O mem
  * @substream: PCM substream
  * @area: VMA
  *
  * When your hardware uses the iomapped pages as the hardware buffer and
  * wants to mmap it, pass this function as mmap pcm_ops.  Note that this
  * is supposed to work only on limited architectures.
  *
  * Return: zero if successful, or a negative error code
  */
 int snd_pcm_lib_mmap_iomem(struct snd_pcm_substream *substream,
                struct vm_area_struct *area)
 {
     struct snd_pcm_runtime *runtime = substream->runtime;
 
     area->vm_page_prot = pgprot_noncached(area->vm_page_prot);
     return vm_iomap_memory(area, runtime->dma_addr, runtime->dma_bytes);
 }
 EXPORT_SYMBOL(snd_pcm_lib_mmap_iomem);
 #endif /* SNDRV_PCM_INFO_MMAP */
 
 /*
  * mmap DMA buffer
  */
 int snd_pcm_mmap_data(struct snd_pcm_substream *substream, struct file *file,
               struct vm_area_struct *area)
 {
     struct snd_pcm_runtime *runtime;
     long size;
     unsigned long offset;
     size_t dma_bytes;
     int err;
 
     if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
         if (!(area->vm_flags & (VM_WRITE|VM_READ)))
             return -EINVAL;
     } else {
         if (!(area->vm_flags & VM_READ))
             return -EINVAL;
     }
     runtime = substream->runtime;
     if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
         return -EBADFD;
     if (!(runtime->info & SNDRV_PCM_INFO_MMAP))
         return -ENXIO;
     if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
         runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
         return -EINVAL;
     size = area->vm_end - area->vm_start;
     offset = area->vm_pgoff << PAGE_SHIFT;
     dma_bytes = PAGE_ALIGN(runtime->dma_bytes);
     if ((size_t)size > dma_bytes)
         return -EINVAL;
     if (offset > dma_bytes - size)
         return -EINVAL;
 
     area->vm_ops = &snd_pcm_vm_ops_data;
     area->vm_private_data = substream;
     if (substream->ops->mmap)
         err = substream->ops->mmap(substream, area);
     else
         err = snd_pcm_lib_default_mmap(substream, area);
     if (!err)
         atomic_inc(&substream->mmap_count);
     return err;
 }
 EXPORT_SYMBOL(snd_pcm_mmap_data);
 
 static int snd_pcm_mmap(struct file *file, struct vm_area_struct *area)
 {
     struct snd_pcm_file * pcm_file;
     struct snd_pcm_substream *substream;    
     unsigned long offset;
     
     pcm_file = file->private_data;
     substream = pcm_file->substream;
     if (PCM_RUNTIME_CHECK(substream))
         return -ENXIO;
     if (substream->runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
         return -EBADFD;
 
     offset = area->vm_pgoff << PAGE_SHIFT;
     switch (offset) {
     case SNDRV_PCM_MMAP_OFFSET_STATUS_OLD:
         if (pcm_file->no_compat_mmap || !IS_ENABLED(CONFIG_64BIT))
             return -ENXIO;
         fallthrough;
     case SNDRV_PCM_MMAP_OFFSET_STATUS_NEW:
         if (!pcm_status_mmap_allowed(pcm_file))
             return -ENXIO;
         return snd_pcm_mmap_status(substream, file, area);
     case SNDRV_PCM_MMAP_OFFSET_CONTROL_OLD:
         if (pcm_file->no_compat_mmap || !IS_ENABLED(CONFIG_64BIT))
             return -ENXIO;
         fallthrough;
     case SNDRV_PCM_MMAP_OFFSET_CONTROL_NEW:
         if (!pcm_control_mmap_allowed(pcm_file))
             return -ENXIO;
         return snd_pcm_mmap_control(substream, file, area);
     default:
         return snd_pcm_mmap_data(substream, file, area);
     }
     return 0;
 }
 
 static int snd_pcm_fasync(int fd, struct file * file, int on)
 {
     struct snd_pcm_file * pcm_file;
     struct snd_pcm_substream *substream;
     struct snd_pcm_runtime *runtime;
 
     pcm_file = file->private_data;
     substream = pcm_file->substream;
     if (PCM_RUNTIME_CHECK(substream))
         return -ENXIO;
     runtime = substream->runtime;
     if (runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
         return -EBADFD;
     return snd_fasync_helper(fd, file, on, &runtime->fasync);
 }
 
 /*
  * ioctl32 compat
  */
 #ifdef CONFIG_COMPAT
 #include "pcm_compat.c"
 #else
 #define snd_pcm_ioctl_compat    NULL
 #endif
 
 /*
  *  To be removed helpers to keep binary compatibility
  */
 
 #ifdef CONFIG_SND_SUPPORT_OLD_API
 #define __OLD_TO_NEW_MASK(x) ((x&7)|((x&0x07fffff8)<<5))
 #define __NEW_TO_OLD_MASK(x) ((x&7)|((x&0xffffff00)>>5))
 
 static void snd_pcm_hw_convert_from_old_params(struct snd_pcm_hw_params *params,
                            struct snd_pcm_hw_params_old *oparams)
 {
     unsigned int i;
 
     memset(params, 0, sizeof(*params));
     params->flags = oparams->flags;
     for (i = 0; i < ARRAY_SIZE(oparams->masks); i++)
         params->masks[i].bits[0] = oparams->masks[i];
     memcpy(params->intervals, oparams->intervals, sizeof(oparams->intervals));
     params->rmask = __OLD_TO_NEW_MASK(oparams->rmask);
     params->cmask = __OLD_TO_NEW_MASK(oparams->cmask);
     params->info = oparams->info;
     params->msbits = oparams->msbits;
     params->rate_num = oparams->rate_num;
     params->rate_den = oparams->rate_den;
     params->fifo_size = oparams->fifo_size;
 }
 
 static void snd_pcm_hw_convert_to_old_params(struct snd_pcm_hw_params_old *oparams,
                          struct snd_pcm_hw_params *params)
 {
     unsigned int i;
 
     memset(oparams, 0, sizeof(*oparams));
     oparams->flags = params->flags;
     for (i = 0; i < ARRAY_SIZE(oparams->masks); i++)
         oparams->masks[i] = params->masks[i].bits[0];
     memcpy(oparams->intervals, params->intervals, sizeof(oparams->intervals));
     oparams->rmask = __NEW_TO_OLD_MASK(params->rmask);
     oparams->cmask = __NEW_TO_OLD_MASK(params->cmask);
     oparams->info = params->info;
     oparams->msbits = params->msbits;
     oparams->rate_num = params->rate_num;
     oparams->rate_den = params->rate_den;
     oparams->fifo_size = params->fifo_size;
 }
 
 static int snd_pcm_hw_refine_old_user(struct snd_pcm_substream *substream,
                       struct snd_pcm_hw_params_old __user * _oparams)
 {
     struct snd_pcm_hw_params *params;
     struct snd_pcm_hw_params_old *oparams = NULL;
     int err;
 
     params = kmalloc(sizeof(*params), GFP_KERNEL);
     if (!params)
         return -ENOMEM;
 
     oparams = memdup_user(_oparams, sizeof(*oparams));
     if (IS_ERR(oparams)) {
         err = PTR_ERR(oparams);
         goto out;
     }
     snd_pcm_hw_convert_from_old_params(params, oparams);
     err = snd_pcm_hw_refine(substream, params);
     if (err < 0)
         goto out_old;
 
     err = fixup_unreferenced_params(substream, params);
     if (err < 0)
         goto out_old;
 
     snd_pcm_hw_convert_to_old_params(oparams, params);
     if (copy_to_user(_oparams, oparams, sizeof(*oparams)))
         err = -EFAULT;
 out_old:
     kfree(oparams);
 out:
     kfree(params);
     return err;
 }
 
 static int snd_pcm_hw_params_old_user(struct snd_pcm_substream *substream,
                       struct snd_pcm_hw_params_old __user * _oparams)
 {
     struct snd_pcm_hw_params *params;
     struct snd_pcm_hw_params_old *oparams = NULL;
     int err;
 
     params = kmalloc(sizeof(*params), GFP_KERNEL);
     if (!params)
         return -ENOMEM;
 
     oparams = memdup_user(_oparams, sizeof(*oparams));
     if (IS_ERR(oparams)) {
         err = PTR_ERR(oparams);
         goto out;
     }
 
     snd_pcm_hw_convert_from_old_params(params, oparams);
     err = snd_pcm_hw_params(substream, params);
     if (err < 0)
         goto out_old;
 
     snd_pcm_hw_convert_to_old_params(oparams, params);
     if (copy_to_user(_oparams, oparams, sizeof(*oparams)))
         err = -EFAULT;
 out_old:
     kfree(oparams);
 out:
     kfree(params);
     return err;
 }
 #endif /* CONFIG_SND_SUPPORT_OLD_API */
 
 #ifndef CONFIG_MMU
 static unsigned long snd_pcm_get_unmapped_area(struct file *file,
                            unsigned long addr,
                            unsigned long len,
                            unsigned long pgoff,
                            unsigned long flags)
 {
     struct snd_pcm_file *pcm_file = file->private_data;
     struct snd_pcm_substream *substream = pcm_file->substream;
     struct snd_pcm_runtime *runtime = substream->runtime;
     unsigned long offset = pgoff << PAGE_SHIFT;
 
     switch (offset) {
     case SNDRV_PCM_MMAP_OFFSET_STATUS_NEW:
         return (unsigned long)runtime->status;
     case SNDRV_PCM_MMAP_OFFSET_CONTROL_NEW:
         return (unsigned long)runtime->control;
     default:
         return (unsigned long)runtime->dma_area + offset;
     }
 }
 #else
 # define snd_pcm_get_unmapped_area NULL
 #endif
 
 /*
  *  Register section
  */
 
 const struct file_operations snd_pcm_f_ops[2] = {
     {
         .owner =        THIS_MODULE,
         .write =        snd_pcm_write,
         .write_iter =       snd_pcm_writev,
         .open =         snd_pcm_playback_open,
         .release =      snd_pcm_release,
         .llseek =       no_llseek,
         .poll =         snd_pcm_poll,
         .unlocked_ioctl =   snd_pcm_ioctl,
         .compat_ioctl =     snd_pcm_ioctl_compat,
         .mmap =         snd_pcm_mmap,
         .fasync =       snd_pcm_fasync,
         .get_unmapped_area =    snd_pcm_get_unmapped_area,
     },
     {
         .owner =        THIS_MODULE,
         .read =         snd_pcm_read,
         .read_iter =        snd_pcm_readv,
         .open =         snd_pcm_capture_open,
         .release =      snd_pcm_release,
         .llseek =       no_llseek,
         .poll =         snd_pcm_poll,
         .unlocked_ioctl =   snd_pcm_ioctl,
         .compat_ioctl =     snd_pcm_ioctl_compat,
         .mmap =         snd_pcm_mmap,
         .fasync =       snd_pcm_fasync,
         .get_unmapped_area =    snd_pcm_get_unmapped_area,
     }
 };