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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-only
 /* esp_scsi.c: ESP SCSI driver.
  *
  * Copyright (C) 2007 David S. Miller (davem@davemloft.net)
  */
 
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/list.h>
 #include <linux/completion.h>
 #include <linux/kallsyms.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/init.h>
 #include <linux/irqreturn.h>
 
 #include <asm/irq.h>
 #include <asm/io.h>
 #include <asm/dma.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_tcq.h>
 #include <scsi/scsi_dbg.h>
 #include <scsi/scsi_transport_spi.h>
 
 #include "esp_scsi.h"
 
 #define DRV_MODULE_NAME     "esp"
 #define PFX DRV_MODULE_NAME ": "
 #define DRV_VERSION     "2.000"
 #define DRV_MODULE_RELDATE  "April 19, 2007"
 
 /* SCSI bus reset settle time in seconds.  */
 static int esp_bus_reset_settle = 3;
 
 static u32 esp_debug;
 #define ESP_DEBUG_INTR      0x00000001
 #define ESP_DEBUG_SCSICMD   0x00000002
 #define ESP_DEBUG_RESET     0x00000004
 #define ESP_DEBUG_MSGIN     0x00000008
 #define ESP_DEBUG_MSGOUT    0x00000010
 #define ESP_DEBUG_CMDDONE   0x00000020
 #define ESP_DEBUG_DISCONNECT    0x00000040
 #define ESP_DEBUG_DATASTART 0x00000080
 #define ESP_DEBUG_DATADONE  0x00000100
 #define ESP_DEBUG_RECONNECT 0x00000200
 #define ESP_DEBUG_AUTOSENSE 0x00000400
 #define ESP_DEBUG_EVENT     0x00000800
 #define ESP_DEBUG_COMMAND   0x00001000
 
 #define esp_log_intr(f, a...) \
 do {    if (esp_debug & ESP_DEBUG_INTR) \
         shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
 } while (0)
 
 #define esp_log_reset(f, a...) \
 do {    if (esp_debug & ESP_DEBUG_RESET) \
         shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
 } while (0)
 
 #define esp_log_msgin(f, a...) \
 do {    if (esp_debug & ESP_DEBUG_MSGIN) \
         shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
 } while (0)
 
 #define esp_log_msgout(f, a...) \
 do {    if (esp_debug & ESP_DEBUG_MSGOUT) \
         shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
 } while (0)
 
 #define esp_log_cmddone(f, a...) \
 do {    if (esp_debug & ESP_DEBUG_CMDDONE) \
         shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
 } while (0)
 
 #define esp_log_disconnect(f, a...) \
 do {    if (esp_debug & ESP_DEBUG_DISCONNECT) \
         shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
 } while (0)
 
 #define esp_log_datastart(f, a...) \
 do {    if (esp_debug & ESP_DEBUG_DATASTART) \
         shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
 } while (0)
 
 #define esp_log_datadone(f, a...) \
 do {    if (esp_debug & ESP_DEBUG_DATADONE) \
         shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
 } while (0)
 
 #define esp_log_reconnect(f, a...) \
 do {    if (esp_debug & ESP_DEBUG_RECONNECT) \
         shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
 } while (0)
 
 #define esp_log_autosense(f, a...) \
 do {    if (esp_debug & ESP_DEBUG_AUTOSENSE) \
         shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
 } while (0)
 
 #define esp_log_event(f, a...) \
 do {   if (esp_debug & ESP_DEBUG_EVENT) \
         shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
 } while (0)
 
 #define esp_log_command(f, a...) \
 do {   if (esp_debug & ESP_DEBUG_COMMAND)   \
         shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
 } while (0)
 
 #define esp_read8(REG)      esp->ops->esp_read8(esp, REG)
 #define esp_write8(VAL,REG) esp->ops->esp_write8(esp, VAL, REG)
 
 static void esp_log_fill_regs(struct esp *esp,
                   struct esp_event_ent *p)
 {
     p->sreg = esp->sreg;
     p->seqreg = esp->seqreg;
     p->sreg2 = esp->sreg2;
     p->ireg = esp->ireg;
     p->select_state = esp->select_state;
     p->event = esp->event;
 }
 
 void scsi_esp_cmd(struct esp *esp, u8 val)
 {
     struct esp_event_ent *p;
     int idx = esp->esp_event_cur;
 
     p = &esp->esp_event_log[idx];
     p->type = ESP_EVENT_TYPE_CMD;
     p->val = val;
     esp_log_fill_regs(esp, p);
 
     esp->esp_event_cur = (idx + 1) & (ESP_EVENT_LOG_SZ - 1);
 
     esp_log_command("cmd[%02x]\n", val);
     esp_write8(val, ESP_CMD);
 }
 EXPORT_SYMBOL(scsi_esp_cmd);
 
 static void esp_send_dma_cmd(struct esp *esp, int len, int max_len, int cmd)
 {
     if (esp->flags & ESP_FLAG_USE_FIFO) {
         int i;
 
         scsi_esp_cmd(esp, ESP_CMD_FLUSH);
         for (i = 0; i < len; i++)
             esp_write8(esp->command_block[i], ESP_FDATA);
         scsi_esp_cmd(esp, cmd);
     } else {
         if (esp->rev == FASHME)
             scsi_esp_cmd(esp, ESP_CMD_FLUSH);
         cmd |= ESP_CMD_DMA;
         esp->ops->send_dma_cmd(esp, esp->command_block_dma,
                        len, max_len, 0, cmd);
     }
 }
 
 static void esp_event(struct esp *esp, u8 val)
 {
     struct esp_event_ent *p;
     int idx = esp->esp_event_cur;
 
     p = &esp->esp_event_log[idx];
     p->type = ESP_EVENT_TYPE_EVENT;
     p->val = val;
     esp_log_fill_regs(esp, p);
 
     esp->esp_event_cur = (idx + 1) & (ESP_EVENT_LOG_SZ - 1);
 
     esp->event = val;
 }
 
 static void esp_dump_cmd_log(struct esp *esp)
 {
     int idx = esp->esp_event_cur;
     int stop = idx;
 
     shost_printk(KERN_INFO, esp->host, "Dumping command log\n");
     do {
         struct esp_event_ent *p = &esp->esp_event_log[idx];
 
         shost_printk(KERN_INFO, esp->host,
                  "ent[%d] %s val[%02x] sreg[%02x] seqreg[%02x] "
                  "sreg2[%02x] ireg[%02x] ss[%02x] event[%02x]\n",
                  idx,
                  p->type == ESP_EVENT_TYPE_CMD ? "CMD" : "EVENT",
                  p->val, p->sreg, p->seqreg,
                  p->sreg2, p->ireg, p->select_state, p->event);
 
         idx = (idx + 1) & (ESP_EVENT_LOG_SZ - 1);
     } while (idx != stop);
 }
 
 static void esp_flush_fifo(struct esp *esp)
 {
     scsi_esp_cmd(esp, ESP_CMD_FLUSH);
     if (esp->rev == ESP236) {
         int lim = 1000;
 
         while (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES) {
             if (--lim == 0) {
                 shost_printk(KERN_ALERT, esp->host,
                          "ESP_FF_BYTES will not clear!\n");
                 break;
             }
             udelay(1);
         }
     }
 }
 
 static void hme_read_fifo(struct esp *esp)
 {
     int fcnt = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
     int idx = 0;
 
     while (fcnt--) {
         esp->fifo[idx++] = esp_read8(ESP_FDATA);
         esp->fifo[idx++] = esp_read8(ESP_FDATA);
     }
     if (esp->sreg2 & ESP_STAT2_F1BYTE) {
         esp_write8(0, ESP_FDATA);
         esp->fifo[idx++] = esp_read8(ESP_FDATA);
         scsi_esp_cmd(esp, ESP_CMD_FLUSH);
     }
     esp->fifo_cnt = idx;
 }
 
 static void esp_set_all_config3(struct esp *esp, u8 val)
 {
     int i;
 
     for (i = 0; i < ESP_MAX_TARGET; i++)
         esp->target[i].esp_config3 = val;
 }
 
 /* Reset the ESP chip, _not_ the SCSI bus. */
 static void esp_reset_esp(struct esp *esp)
 {
     /* Now reset the ESP chip */
     scsi_esp_cmd(esp, ESP_CMD_RC);
     scsi_esp_cmd(esp, ESP_CMD_NULL | ESP_CMD_DMA);
     if (esp->rev == FAST)
         esp_write8(ESP_CONFIG2_FENAB, ESP_CFG2);
     scsi_esp_cmd(esp, ESP_CMD_NULL | ESP_CMD_DMA);
 
     /* This is the only point at which it is reliable to read
      * the ID-code for a fast ESP chip variants.
      */
     esp->max_period = ((35 * esp->ccycle) / 1000);
     if (esp->rev == FAST) {
         u8 family_code = ESP_FAMILY(esp_read8(ESP_UID));
 
         if (family_code == ESP_UID_F236) {
             esp->rev = FAS236;
         } else if (family_code == ESP_UID_HME) {
             esp->rev = FASHME; /* Version is usually '5'. */
         } else if (family_code == ESP_UID_FSC) {
             esp->rev = FSC;
             /* Enable Active Negation */
             esp_write8(ESP_CONFIG4_RADE, ESP_CFG4);
         } else {
             esp->rev = FAS100A;
         }
         esp->min_period = ((4 * esp->ccycle) / 1000);
     } else {
         esp->min_period = ((5 * esp->ccycle) / 1000);
     }
     if (esp->rev == FAS236) {
         /*
          * The AM53c974 chip returns the same ID as FAS236;
          * try to configure glitch eater.
          */
         u8 config4 = ESP_CONFIG4_GE1;
         esp_write8(config4, ESP_CFG4);
         config4 = esp_read8(ESP_CFG4);
         if (config4 & ESP_CONFIG4_GE1) {
             esp->rev = PCSCSI;
             esp_write8(esp->config4, ESP_CFG4);
         }
     }
     esp->max_period = (esp->max_period + 3)>>2;
     esp->min_period = (esp->min_period + 3)>>2;
 
     esp_write8(esp->config1, ESP_CFG1);
     switch (esp->rev) {
     case ESP100:
         /* nothing to do */
         break;
 
     case ESP100A:
         esp_write8(esp->config2, ESP_CFG2);
         break;
 
     case ESP236:
         /* Slow 236 */
         esp_write8(esp->config2, ESP_CFG2);
         esp->prev_cfg3 = esp->target[0].esp_config3;
         esp_write8(esp->prev_cfg3, ESP_CFG3);
         break;
 
     case FASHME:
         esp->config2 |= (ESP_CONFIG2_HME32 | ESP_CONFIG2_HMEFENAB);
         fallthrough;
 
     case FAS236:
     case PCSCSI:
     case FSC:
         esp_write8(esp->config2, ESP_CFG2);
         if (esp->rev == FASHME) {
             u8 cfg3 = esp->target[0].esp_config3;
 
             cfg3 |= ESP_CONFIG3_FCLOCK | ESP_CONFIG3_OBPUSH;
             if (esp->scsi_id >= 8)
                 cfg3 |= ESP_CONFIG3_IDBIT3;
             esp_set_all_config3(esp, cfg3);
         } else {
             u32 cfg3 = esp->target[0].esp_config3;
 
             cfg3 |= ESP_CONFIG3_FCLK;
             esp_set_all_config3(esp, cfg3);
         }
         esp->prev_cfg3 = esp->target[0].esp_config3;
         esp_write8(esp->prev_cfg3, ESP_CFG3);
         if (esp->rev == FASHME) {
             esp->radelay = 80;
         } else {
             if (esp->flags & ESP_FLAG_DIFFERENTIAL)
                 esp->radelay = 0;
             else
                 esp->radelay = 96;
         }
         break;
 
     case FAS100A:
         /* Fast 100a */
         esp_write8(esp->config2, ESP_CFG2);
         esp_set_all_config3(esp,
                     (esp->target[0].esp_config3 |
                      ESP_CONFIG3_FCLOCK));
         esp->prev_cfg3 = esp->target[0].esp_config3;
         esp_write8(esp->prev_cfg3, ESP_CFG3);
         esp->radelay = 32;
         break;
 
     default:
         break;
     }
 
     /* Reload the configuration registers */
     esp_write8(esp->cfact, ESP_CFACT);
 
     esp->prev_stp = 0;
     esp_write8(esp->prev_stp, ESP_STP);
 
     esp->prev_soff = 0;
     esp_write8(esp->prev_soff, ESP_SOFF);
 
     esp_write8(esp->neg_defp, ESP_TIMEO);
 
     /* Eat any bitrot in the chip */
     esp_read8(ESP_INTRPT);
     udelay(100);
 }
 
 static void esp_map_dma(struct esp *esp, struct scsi_cmnd *cmd)
 {
     struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
     struct scatterlist *sg = scsi_sglist(cmd);
     int total = 0, i;
     struct scatterlist *s;
 
     if (cmd->sc_data_direction == DMA_NONE)
         return;
 
     if (esp->flags & ESP_FLAG_NO_DMA_MAP) {
         /*
          * For pseudo DMA and PIO we need the virtual address instead of
          * a dma address, so perform an identity mapping.
          */
         spriv->num_sg = scsi_sg_count(cmd);
 
         scsi_for_each_sg(cmd, s, spriv->num_sg, i) {
             s->dma_address = (uintptr_t)sg_virt(s);
             total += sg_dma_len(s);
         }
     } else {
         spriv->num_sg = scsi_dma_map(cmd);
         scsi_for_each_sg(cmd, s, spriv->num_sg, i)
             total += sg_dma_len(s);
     }
     spriv->cur_residue = sg_dma_len(sg);
     spriv->prv_sg = NULL;
     spriv->cur_sg = sg;
     spriv->tot_residue = total;
 }
 
 static dma_addr_t esp_cur_dma_addr(struct esp_cmd_entry *ent,
                    struct scsi_cmnd *cmd)
 {
     struct esp_cmd_priv *p = ESP_CMD_PRIV(cmd);
 
     if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
         return ent->sense_dma +
             (ent->sense_ptr - cmd->sense_buffer);
     }
 
     return sg_dma_address(p->cur_sg) +
         (sg_dma_len(p->cur_sg) -
          p->cur_residue);
 }
 
 static unsigned int esp_cur_dma_len(struct esp_cmd_entry *ent,
                     struct scsi_cmnd *cmd)
 {
     struct esp_cmd_priv *p = ESP_CMD_PRIV(cmd);
 
     if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
         return SCSI_SENSE_BUFFERSIZE -
             (ent->sense_ptr - cmd->sense_buffer);
     }
     return p->cur_residue;
 }
 
 static void esp_advance_dma(struct esp *esp, struct esp_cmd_entry *ent,
                 struct scsi_cmnd *cmd, unsigned int len)
 {
     struct esp_cmd_priv *p = ESP_CMD_PRIV(cmd);
 
     if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
         ent->sense_ptr += len;
         return;
     }
 
     p->cur_residue -= len;
     p->tot_residue -= len;
     if (p->cur_residue < 0 || p->tot_residue < 0) {
         shost_printk(KERN_ERR, esp->host,
                  "Data transfer overflow.\n");
         shost_printk(KERN_ERR, esp->host,
                  "cur_residue[%d] tot_residue[%d] len[%u]\n",
                  p->cur_residue, p->tot_residue, len);
         p->cur_residue = 0;
         p->tot_residue = 0;
     }
     if (!p->cur_residue && p->tot_residue) {
         p->prv_sg = p->cur_sg;
         p->cur_sg = sg_next(p->cur_sg);
         p->cur_residue = sg_dma_len(p->cur_sg);
     }
 }
 
 static void esp_unmap_dma(struct esp *esp, struct scsi_cmnd *cmd)
 {
     if (!(esp->flags & ESP_FLAG_NO_DMA_MAP))
         scsi_dma_unmap(cmd);
 }
 
 static void esp_save_pointers(struct esp *esp, struct esp_cmd_entry *ent)
 {
     struct scsi_cmnd *cmd = ent->cmd;
     struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
 
     if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
         ent->saved_sense_ptr = ent->sense_ptr;
         return;
     }
     ent->saved_cur_residue = spriv->cur_residue;
     ent->saved_prv_sg = spriv->prv_sg;
     ent->saved_cur_sg = spriv->cur_sg;
     ent->saved_tot_residue = spriv->tot_residue;
 }
 
 static void esp_restore_pointers(struct esp *esp, struct esp_cmd_entry *ent)
 {
     struct scsi_cmnd *cmd = ent->cmd;
     struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
 
     if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
         ent->sense_ptr = ent->saved_sense_ptr;
         return;
     }
     spriv->cur_residue = ent->saved_cur_residue;
     spriv->prv_sg = ent->saved_prv_sg;
     spriv->cur_sg = ent->saved_cur_sg;
     spriv->tot_residue = ent->saved_tot_residue;
 }
 
 static void esp_write_tgt_config3(struct esp *esp, int tgt)
 {
     if (esp->rev > ESP100A) {
         u8 val = esp->target[tgt].esp_config3;
 
         if (val != esp->prev_cfg3) {
             esp->prev_cfg3 = val;
             esp_write8(val, ESP_CFG3);
         }
     }
 }
 
 static void esp_write_tgt_sync(struct esp *esp, int tgt)
 {
     u8 off = esp->target[tgt].esp_offset;
     u8 per = esp->target[tgt].esp_period;
 
     if (off != esp->prev_soff) {
         esp->prev_soff = off;
         esp_write8(off, ESP_SOFF);
     }
     if (per != esp->prev_stp) {
         esp->prev_stp = per;
         esp_write8(per, ESP_STP);
     }
 }
 
 static u32 esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
 {
     if (esp->rev == FASHME) {
         /* Arbitrary segment boundaries, 24-bit counts.  */
         if (dma_len > (1U << 24))
             dma_len = (1U << 24);
     } else {
         u32 base, end;
 
         /* ESP chip limits other variants by 16-bits of transfer
          * count.  Actually on FAS100A and FAS236 we could get
          * 24-bits of transfer count by enabling ESP_CONFIG2_FENAB
          * in the ESP_CFG2 register but that causes other unwanted
          * changes so we don't use it currently.
          */
         if (dma_len > (1U << 16))
             dma_len = (1U << 16);
 
         /* All of the DMA variants hooked up to these chips
          * cannot handle crossing a 24-bit address boundary.
          */
         base = dma_addr & ((1U << 24) - 1U);
         end = base + dma_len;
         if (end > (1U << 24))
             end = (1U <<24);
         dma_len = end - base;
     }
     return dma_len;
 }
 
 static int esp_need_to_nego_wide(struct esp_target_data *tp)
 {
     struct scsi_target *target = tp->starget;
 
     return spi_width(target) != tp->nego_goal_width;
 }
 
 static int esp_need_to_nego_sync(struct esp_target_data *tp)
 {
     struct scsi_target *target = tp->starget;
 
     /* When offset is zero, period is "don't care".  */
     if (!spi_offset(target) && !tp->nego_goal_offset)
         return 0;
 
     if (spi_offset(target) == tp->nego_goal_offset &&
         spi_period(target) == tp->nego_goal_period)
         return 0;
 
     return 1;
 }
 
 static int esp_alloc_lun_tag(struct esp_cmd_entry *ent,
                  struct esp_lun_data *lp)
 {
     if (!ent->orig_tag[0]) {
         /* Non-tagged, slot already taken?  */
         if (lp->non_tagged_cmd)
             return -EBUSY;
 
         if (lp->hold) {
             /* We are being held by active tagged
              * commands.
              */
             if (lp->num_tagged)
                 return -EBUSY;
 
             /* Tagged commands completed, we can unplug
              * the queue and run this untagged command.
              */
             lp->hold = 0;
         } else if (lp->num_tagged) {
             /* Plug the queue until num_tagged decreases
              * to zero in esp_free_lun_tag.
              */
             lp->hold = 1;
             return -EBUSY;
         }
 
         lp->non_tagged_cmd = ent;
         return 0;
     }
 
     /* Tagged command. Check that it isn't blocked by a non-tagged one. */
     if (lp->non_tagged_cmd || lp->hold)
         return -EBUSY;
 
     BUG_ON(lp->tagged_cmds[ent->orig_tag[1]]);
 
     lp->tagged_cmds[ent->orig_tag[1]] = ent;
     lp->num_tagged++;
 
     return 0;
 }
 
 static void esp_free_lun_tag(struct esp_cmd_entry *ent,
                  struct esp_lun_data *lp)
 {
     if (ent->orig_tag[0]) {
         BUG_ON(lp->tagged_cmds[ent->orig_tag[1]] != ent);
         lp->tagged_cmds[ent->orig_tag[1]] = NULL;
         lp->num_tagged--;
     } else {
         BUG_ON(lp->non_tagged_cmd != ent);
         lp->non_tagged_cmd = NULL;
     }
 }
 
 static void esp_map_sense(struct esp *esp, struct esp_cmd_entry *ent)
 {
     ent->sense_ptr = ent->cmd->sense_buffer;
     if (esp->flags & ESP_FLAG_NO_DMA_MAP) {
         ent->sense_dma = (uintptr_t)ent->sense_ptr;
         return;
     }
 
     ent->sense_dma = dma_map_single(esp->dev, ent->sense_ptr,
                     SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
 }
 
 static void esp_unmap_sense(struct esp *esp, struct esp_cmd_entry *ent)
 {
     if (!(esp->flags & ESP_FLAG_NO_DMA_MAP))
         dma_unmap_single(esp->dev, ent->sense_dma,
                  SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
     ent->sense_ptr = NULL;
 }
 
 /* When a contingent allegiance condition is created, we force feed a
  * REQUEST_SENSE command to the device to fetch the sense data.  I
  * tried many other schemes, relying on the scsi error handling layer
  * to send out the REQUEST_SENSE automatically, but this was difficult
  * to get right especially in the presence of applications like smartd
  * which use SG_IO to send out their own REQUEST_SENSE commands.
  */
 static void esp_autosense(struct esp *esp, struct esp_cmd_entry *ent)
 {
     struct scsi_cmnd *cmd = ent->cmd;
     struct scsi_device *dev = cmd->device;
     int tgt, lun;
     u8 *p, val;
 
     tgt = dev->id;
     lun = dev->lun;
 
 
     if (!ent->sense_ptr) {
         esp_log_autosense("Doing auto-sense for tgt[%d] lun[%d]\n",
                   tgt, lun);
         esp_map_sense(esp, ent);
     }
     ent->saved_sense_ptr = ent->sense_ptr;
 
     esp->active_cmd = ent;
 
     p = esp->command_block;
     esp->msg_out_len = 0;
 
     *p++ = IDENTIFY(0, lun);
     *p++ = REQUEST_SENSE;
     *p++ = ((dev->scsi_level <= SCSI_2) ?
         (lun << 5) : 0);
     *p++ = 0;
     *p++ = 0;
     *p++ = SCSI_SENSE_BUFFERSIZE;
     *p++ = 0;
 
     esp->select_state = ESP_SELECT_BASIC;
 
     val = tgt;
     if (esp->rev == FASHME)
         val |= ESP_BUSID_RESELID | ESP_BUSID_CTR32BIT;
     esp_write8(val, ESP_BUSID);
 
     esp_write_tgt_sync(esp, tgt);
     esp_write_tgt_config3(esp, tgt);
 
     val = (p - esp->command_block);
 
     esp_send_dma_cmd(esp, val, 16, ESP_CMD_SELA);
 }
 
 static struct esp_cmd_entry *find_and_prep_issuable_command(struct esp *esp)
 {
     struct esp_cmd_entry *ent;
 
     list_for_each_entry(ent, &esp->queued_cmds, list) {
         struct scsi_cmnd *cmd = ent->cmd;
         struct scsi_device *dev = cmd->device;
         struct esp_lun_data *lp = dev->hostdata;
 
         if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
             ent->tag[0] = 0;
             ent->tag[1] = 0;
             return ent;
         }
 
         if (!spi_populate_tag_msg(&ent->tag[0], cmd)) {
             ent->tag[0] = 0;
             ent->tag[1] = 0;
         }
         ent->orig_tag[0] = ent->tag[0];
         ent->orig_tag[1] = ent->tag[1];
 
         if (esp_alloc_lun_tag(ent, lp) < 0)
             continue;
 
         return ent;
     }
 
     return NULL;
 }
 
 static void esp_maybe_execute_command(struct esp *esp)
 {
     struct esp_target_data *tp;
     struct scsi_device *dev;
     struct scsi_cmnd *cmd;
     struct esp_cmd_entry *ent;
     bool select_and_stop = false;
     int tgt, lun, i;
     u32 val, start_cmd;
     u8 *p;
 
     if (esp->active_cmd ||
         (esp->flags & ESP_FLAG_RESETTING))
         return;
 
     ent = find_and_prep_issuable_command(esp);
     if (!ent)
         return;
 
     if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
         esp_autosense(esp, ent);
         return;
     }
 
     cmd = ent->cmd;
     dev = cmd->device;
     tgt = dev->id;
     lun = dev->lun;
     tp = &esp->target[tgt];
 
     list_move(&ent->list, &esp->active_cmds);
 
     esp->active_cmd = ent;
 
     esp_map_dma(esp, cmd);
     esp_save_pointers(esp, ent);
 
     if (!(cmd->cmd_len == 6 || cmd->cmd_len == 10 || cmd->cmd_len == 12))
         select_and_stop = true;
 
     p = esp->command_block;
 
     esp->msg_out_len = 0;
     if (tp->flags & ESP_TGT_CHECK_NEGO) {
         /* Need to negotiate.  If the target is broken
          * go for synchronous transfers and non-wide.
          */
         if (tp->flags & ESP_TGT_BROKEN) {
             tp->flags &= ~ESP_TGT_DISCONNECT;
             tp->nego_goal_period = 0;
             tp->nego_goal_offset = 0;
             tp->nego_goal_width = 0;
             tp->nego_goal_tags = 0;
         }
 
         /* If the settings are not changing, skip this.  */
         if (spi_width(tp->starget) == tp->nego_goal_width &&
             spi_period(tp->starget) == tp->nego_goal_period &&
             spi_offset(tp->starget) == tp->nego_goal_offset) {
             tp->flags &= ~ESP_TGT_CHECK_NEGO;
             goto build_identify;
         }
 
         if (esp->rev == FASHME && esp_need_to_nego_wide(tp)) {
             esp->msg_out_len =
                 spi_populate_width_msg(&esp->msg_out[0],
                                (tp->nego_goal_width ?
                             1 : 0));
             tp->flags |= ESP_TGT_NEGO_WIDE;
         } else if (esp_need_to_nego_sync(tp)) {
             esp->msg_out_len =
                 spi_populate_sync_msg(&esp->msg_out[0],
                               tp->nego_goal_period,
                               tp->nego_goal_offset);
             tp->flags |= ESP_TGT_NEGO_SYNC;
         } else {
             tp->flags &= ~ESP_TGT_CHECK_NEGO;
         }
 
         /* If there are multiple message bytes, use Select and Stop */
         if (esp->msg_out_len)
             select_and_stop = true;
     }
 
 build_identify:
     *p++ = IDENTIFY(tp->flags & ESP_TGT_DISCONNECT, lun);
 
     if (ent->tag[0] && esp->rev == ESP100) {
         /* ESP100 lacks select w/atn3 command, use select
          * and stop instead.
          */
         select_and_stop = true;
     }
 
     if (select_and_stop) {
         esp->cmd_bytes_left = cmd->cmd_len;
         esp->cmd_bytes_ptr = &cmd->cmnd[0];
 
         if (ent->tag[0]) {
             for (i = esp->msg_out_len - 1;
                  i >= 0; i--)
                 esp->msg_out[i + 2] = esp->msg_out[i];
             esp->msg_out[0] = ent->tag[0];
             esp->msg_out[1] = ent->tag[1];
             esp->msg_out_len += 2;
         }
 
         start_cmd = ESP_CMD_SELAS;
         esp->select_state = ESP_SELECT_MSGOUT;
     } else {
         start_cmd = ESP_CMD_SELA;
         if (ent->tag[0]) {
             *p++ = ent->tag[0];
             *p++ = ent->tag[1];
 
             start_cmd = ESP_CMD_SA3;
         }
 
         for (i = 0; i < cmd->cmd_len; i++)
             *p++ = cmd->cmnd[i];
 
         esp->select_state = ESP_SELECT_BASIC;
     }
     val = tgt;
     if (esp->rev == FASHME)
         val |= ESP_BUSID_RESELID | ESP_BUSID_CTR32BIT;
     esp_write8(val, ESP_BUSID);
 
     esp_write_tgt_sync(esp, tgt);
     esp_write_tgt_config3(esp, tgt);
 
     val = (p - esp->command_block);
 
     if (esp_debug & ESP_DEBUG_SCSICMD) {
         printk("ESP: tgt[%d] lun[%d] scsi_cmd [ ", tgt, lun);
         for (i = 0; i < cmd->cmd_len; i++)
             printk("%02x ", cmd->cmnd[i]);
         printk("]\n");
     }
 
     esp_send_dma_cmd(esp, val, 16, start_cmd);
 }
 
 static struct esp_cmd_entry *esp_get_ent(struct esp *esp)
 {
     struct list_head *head = &esp->esp_cmd_pool;
     struct esp_cmd_entry *ret;
 
     if (list_empty(head)) {
         ret = kzalloc(sizeof(struct esp_cmd_entry), GFP_ATOMIC);
     } else {
         ret = list_entry(head->next, struct esp_cmd_entry, list);
         list_del(&ret->list);
         memset(ret, 0, sizeof(*ret));
     }
     return ret;
 }
 
 static void esp_put_ent(struct esp *esp, struct esp_cmd_entry *ent)
 {
     list_add(&ent->list, &esp->esp_cmd_pool);
 }
 
 static void esp_cmd_is_done(struct esp *esp, struct esp_cmd_entry *ent,
                 struct scsi_cmnd *cmd, unsigned char host_byte)
 {
     struct scsi_device *dev = cmd->device;
     int tgt = dev->id;
     int lun = dev->lun;
 
     esp->active_cmd = NULL;
     esp_unmap_dma(esp, cmd);
     esp_free_lun_tag(ent, dev->hostdata);
     cmd->result = 0;
     set_host_byte(cmd, host_byte);
     if (host_byte == DID_OK)
         set_status_byte(cmd, ent->status);
 
     if (ent->eh_done) {
         complete(ent->eh_done);
         ent->eh_done = NULL;
     }
 
     if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
         esp_unmap_sense(esp, ent);
 
         /* Restore the message/status bytes to what we actually
          * saw originally.  Also, report that we are providing
          * the sense data.
          */
         cmd->result = SAM_STAT_CHECK_CONDITION;
 
         ent->flags &= ~ESP_CMD_FLAG_AUTOSENSE;
         if (esp_debug & ESP_DEBUG_AUTOSENSE) {
             int i;
 
             printk("esp%d: tgt[%d] lun[%d] AUTO SENSE[ ",
                    esp->host->unique_id, tgt, lun);
             for (i = 0; i < 18; i++)
                 printk("%02x ", cmd->sense_buffer[i]);
             printk("]\n");
         }
     }
 
     scsi_done(cmd);
 
     list_del(&ent->list);
     esp_put_ent(esp, ent);
 
     esp_maybe_execute_command(esp);
 }
 
 static void esp_event_queue_full(struct esp *esp, struct esp_cmd_entry *ent)
 {
     struct scsi_device *dev = ent->cmd->device;
     struct esp_lun_data *lp = dev->hostdata;
 
     scsi_track_queue_full(dev, lp->num_tagged - 1);
 }
 
 static int esp_queuecommand_lck(struct scsi_cmnd *cmd)
 {
     struct scsi_device *dev = cmd->device;
     struct esp *esp = shost_priv(dev->host);
     struct esp_cmd_priv *spriv;
     struct esp_cmd_entry *ent;
 
     ent = esp_get_ent(esp);
     if (!ent)
         return SCSI_MLQUEUE_HOST_BUSY;
 
     ent->cmd = cmd;
 
     spriv = ESP_CMD_PRIV(cmd);
     spriv->num_sg = 0;
 
     list_add_tail(&ent->list, &esp->queued_cmds);
 
     esp_maybe_execute_command(esp);
 
     return 0;
 }
 
 static DEF_SCSI_QCMD(esp_queuecommand)
 
 static int esp_check_gross_error(struct esp *esp)
 {
     if (esp->sreg & ESP_STAT_SPAM) {
         /* Gross Error, could be one of:
          * - top of fifo overwritten
          * - top of command register overwritten
          * - DMA programmed with wrong direction
          * - improper phase change
          */
         shost_printk(KERN_ERR, esp->host,
                  "Gross error sreg[%02x]\n", esp->sreg);
         /* XXX Reset the chip. XXX */
         return 1;
     }
     return 0;
 }
 
 static int esp_check_spur_intr(struct esp *esp)
 {
     switch (esp->rev) {
     case ESP100:
     case ESP100A:
         /* The interrupt pending bit of the status register cannot
          * be trusted on these revisions.
          */
         esp->sreg &= ~ESP_STAT_INTR;
         break;
 
     default:
         if (!(esp->sreg & ESP_STAT_INTR)) {
             if (esp->ireg & ESP_INTR_SR)
                 return 1;
 
             /* If the DMA is indicating interrupt pending and the
              * ESP is not, the only possibility is a DMA error.
              */
             if (!esp->ops->dma_error(esp)) {
                 shost_printk(KERN_ERR, esp->host,
                          "Spurious irq, sreg=%02x.\n",
                          esp->sreg);
                 return -1;
             }
 
             shost_printk(KERN_ERR, esp->host, "DMA error\n");
 
             /* XXX Reset the chip. XXX */
             return -1;
         }
         break;
     }
 
     return 0;
 }
 
 static void esp_schedule_reset(struct esp *esp)
 {
     esp_log_reset("esp_schedule_reset() from %ps\n",
               __builtin_return_address(0));
     esp->flags |= ESP_FLAG_RESETTING;
     esp_event(esp, ESP_EVENT_RESET);
 }
 
 /* In order to avoid having to add a special half-reconnected state
  * into the driver we just sit here and poll through the rest of
  * the reselection process to get the tag message bytes.
  */
 static struct esp_cmd_entry *esp_reconnect_with_tag(struct esp *esp,
                             struct esp_lun_data *lp)
 {
     struct esp_cmd_entry *ent;
     int i;
 
     if (!lp->num_tagged) {
         shost_printk(KERN_ERR, esp->host,
                  "Reconnect w/num_tagged==0\n");
         return NULL;
     }
 
     esp_log_reconnect("reconnect tag, ");
 
     for (i = 0; i < ESP_QUICKIRQ_LIMIT; i++) {
         if (esp->ops->irq_pending(esp))
             break;
     }
     if (i == ESP_QUICKIRQ_LIMIT) {
         shost_printk(KERN_ERR, esp->host,
                  "Reconnect IRQ1 timeout\n");
         return NULL;
     }
 
     esp->sreg = esp_read8(ESP_STATUS);
     esp->ireg = esp_read8(ESP_INTRPT);
 
     esp_log_reconnect("IRQ(%d:%x:%x), ",
               i, esp->ireg, esp->sreg);
 
     if (esp->ireg & ESP_INTR_DC) {
         shost_printk(KERN_ERR, esp->host,
                  "Reconnect, got disconnect.\n");
         return NULL;
     }
 
     if ((esp->sreg & ESP_STAT_PMASK) != ESP_MIP) {
         shost_printk(KERN_ERR, esp->host,
                  "Reconnect, not MIP sreg[%02x].\n", esp->sreg);
         return NULL;
     }
 
     /* DMA in the tag bytes... */
     esp->command_block[0] = 0xff;
     esp->command_block[1] = 0xff;
     esp->ops->send_dma_cmd(esp, esp->command_block_dma,
                    2, 2, 1, ESP_CMD_DMA | ESP_CMD_TI);
 
     /* ACK the message.  */
     scsi_esp_cmd(esp, ESP_CMD_MOK);
 
     for (i = 0; i < ESP_RESELECT_TAG_LIMIT; i++) {
         if (esp->ops->irq_pending(esp)) {
             esp->sreg = esp_read8(ESP_STATUS);
             esp->ireg = esp_read8(ESP_INTRPT);
             if (esp->ireg & ESP_INTR_FDONE)
                 break;
         }
         udelay(1);
     }
     if (i == ESP_RESELECT_TAG_LIMIT) {
         shost_printk(KERN_ERR, esp->host, "Reconnect IRQ2 timeout\n");
         return NULL;
     }
     esp->ops->dma_drain(esp);
     esp->ops->dma_invalidate(esp);
 
     esp_log_reconnect("IRQ2(%d:%x:%x) tag[%x:%x]\n",
               i, esp->ireg, esp->sreg,
               esp->command_block[0],
               esp->command_block[1]);
 
     if (esp->command_block[0] < SIMPLE_QUEUE_TAG ||
         esp->command_block[0] > ORDERED_QUEUE_TAG) {
         shost_printk(KERN_ERR, esp->host,
                  "Reconnect, bad tag type %02x.\n",
                  esp->command_block[0]);
         return NULL;
     }
 
     ent = lp->tagged_cmds[esp->command_block[1]];
     if (!ent) {
         shost_printk(KERN_ERR, esp->host,
                  "Reconnect, no entry for tag %02x.\n",
                  esp->command_block[1]);
         return NULL;
     }
 
     return ent;
 }
 
 static int esp_reconnect(struct esp *esp)
 {
     struct esp_cmd_entry *ent;
     struct esp_target_data *tp;
     struct esp_lun_data *lp;
     struct scsi_device *dev;
     int target, lun;
 
     BUG_ON(esp->active_cmd);
     if (esp->rev == FASHME) {
         /* FASHME puts the target and lun numbers directly
          * into the fifo.
          */
         target = esp->fifo[0];
         lun = esp->fifo[1] & 0x7;
     } else {
         u8 bits = esp_read8(ESP_FDATA);
 
         /* Older chips put the lun directly into the fifo, but
          * the target is given as a sample of the arbitration
          * lines on the bus at reselection time.  So we should
          * see the ID of the ESP and the one reconnecting target
          * set in the bitmap.
          */
         if (!(bits & esp->scsi_id_mask))
             goto do_reset;
         bits &= ~esp->scsi_id_mask;
         if (!bits || (bits & (bits - 1)))
             goto do_reset;
 
         target = ffs(bits) - 1;
         lun = (esp_read8(ESP_FDATA) & 0x7);
 
         scsi_esp_cmd(esp, ESP_CMD_FLUSH);
         if (esp->rev == ESP100) {
             u8 ireg = esp_read8(ESP_INTRPT);
             /* This chip has a bug during reselection that can
              * cause a spurious illegal-command interrupt, which
              * we simply ACK here.  Another possibility is a bus
              * reset so we must check for that.
              */
             if (ireg & ESP_INTR_SR)
                 goto do_reset;
         }
         scsi_esp_cmd(esp, ESP_CMD_NULL);
     }
 
     esp_write_tgt_sync(esp, target);
     esp_write_tgt_config3(esp, target);
 
     scsi_esp_cmd(esp, ESP_CMD_MOK);
 
     if (esp->rev == FASHME)
         esp_write8(target | ESP_BUSID_RESELID | ESP_BUSID_CTR32BIT,
                ESP_BUSID);
 
     tp = &esp->target[target];
     dev = __scsi_device_lookup_by_target(tp->starget, lun);
     if (!dev) {
         shost_printk(KERN_ERR, esp->host,
                  "Reconnect, no lp tgt[%u] lun[%u]\n",
                  target, lun);
         goto do_reset;
     }
     lp = dev->hostdata;
 
     ent = lp->non_tagged_cmd;
     if (!ent) {
         ent = esp_reconnect_with_tag(esp, lp);
         if (!ent)
             goto do_reset;
     }
 
     esp->active_cmd = ent;
 
     esp_event(esp, ESP_EVENT_CHECK_PHASE);
     esp_restore_pointers(esp, ent);
     esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
     return 1;
 
 do_reset:
     esp_schedule_reset(esp);
     return 0;
 }
 
 static int esp_finish_select(struct esp *esp)
 {
     struct esp_cmd_entry *ent;
     struct scsi_cmnd *cmd;
 
     /* No longer selecting.  */
     esp->select_state = ESP_SELECT_NONE;
 
     esp->seqreg = esp_read8(ESP_SSTEP) & ESP_STEP_VBITS;
     ent = esp->active_cmd;
     cmd = ent->cmd;
 
     if (esp->ops->dma_error(esp)) {
         /* If we see a DMA error during or as a result of selection,
          * all bets are off.
          */
         esp_schedule_reset(esp);
         esp_cmd_is_done(esp, ent, cmd, DID_ERROR);
         return 0;
     }
 
     esp->ops->dma_invalidate(esp);
 
     if (esp->ireg == (ESP_INTR_RSEL | ESP_INTR_FDONE)) {
         struct esp_target_data *tp = &esp->target[cmd->device->id];
 
         /* Carefully back out of the selection attempt.  Release
          * resources (such as DMA mapping & TAG) and reset state (such
          * as message out and command delivery variables).
          */
         if (!(ent->flags & ESP_CMD_FLAG_AUTOSENSE)) {
             esp_unmap_dma(esp, cmd);
             esp_free_lun_tag(ent, cmd->device->hostdata);
             tp->flags &= ~(ESP_TGT_NEGO_SYNC | ESP_TGT_NEGO_WIDE);
             esp->cmd_bytes_ptr = NULL;
             esp->cmd_bytes_left = 0;
         } else {
             esp_unmap_sense(esp, ent);
         }
 
         /* Now that the state is unwound properly, put back onto
          * the issue queue.  This command is no longer active.
          */
         list_move(&ent->list, &esp->queued_cmds);
         esp->active_cmd = NULL;
 
         /* Return value ignored by caller, it directly invokes
          * esp_reconnect().
          */
         return 0;
     }
 
     if (esp->ireg == ESP_INTR_DC) {
         struct scsi_device *dev = cmd->device;
 
         /* Disconnect.  Make sure we re-negotiate sync and
          * wide parameters if this target starts responding
          * again in the future.
          */
         esp->target[dev->id].flags |= ESP_TGT_CHECK_NEGO;
 
         scsi_esp_cmd(esp, ESP_CMD_ESEL);
         esp_cmd_is_done(esp, ent, cmd, DID_BAD_TARGET);
         return 1;
     }
 
     if (esp->ireg == (ESP_INTR_FDONE | ESP_INTR_BSERV)) {
         /* Selection successful.  On pre-FAST chips we have
          * to do a NOP and possibly clean out the FIFO.
          */
         if (esp->rev <= ESP236) {
             int fcnt = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
 
             scsi_esp_cmd(esp, ESP_CMD_NULL);
 
             if (!fcnt &&
                 (!esp->prev_soff ||
                  ((esp->sreg & ESP_STAT_PMASK) != ESP_DIP)))
                 esp_flush_fifo(esp);
         }
 
         /* If we are doing a Select And Stop command, negotiation, etc.
          * we'll do the right thing as we transition to the next phase.
          */
         esp_event(esp, ESP_EVENT_CHECK_PHASE);
         return 0;
     }
 
     shost_printk(KERN_INFO, esp->host,
              "Unexpected selection completion ireg[%x]\n", esp->ireg);
     esp_schedule_reset(esp);
     return 0;
 }
 
 static int esp_data_bytes_sent(struct esp *esp, struct esp_cmd_entry *ent,
                    struct scsi_cmnd *cmd)
 {
     int fifo_cnt, ecount, bytes_sent, flush_fifo;
 
     fifo_cnt = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
     if (esp->prev_cfg3 & ESP_CONFIG3_EWIDE)
         fifo_cnt <<= 1;
 
     ecount = 0;
     if (!(esp->sreg & ESP_STAT_TCNT)) {
         ecount = ((unsigned int)esp_read8(ESP_TCLOW) |
               (((unsigned int)esp_read8(ESP_TCMED)) << 8));
         if (esp->rev == FASHME)
             ecount |= ((unsigned int)esp_read8(FAS_RLO)) << 16;
         if (esp->rev == PCSCSI && (esp->config2 & ESP_CONFIG2_FENAB))
             ecount |= ((unsigned int)esp_read8(ESP_TCHI)) << 16;
     }
 
     bytes_sent = esp->data_dma_len;
     bytes_sent -= ecount;
     bytes_sent -= esp->send_cmd_residual;
 
     /*
      * The am53c974 has a DMA 'peculiarity'. The doc states:
      * In some odd byte conditions, one residual byte will
      * be left in the SCSI FIFO, and the FIFO Flags will
      * never count to '0 '. When this happens, the residual
      * byte should be retrieved via PIO following completion
      * of the BLAST operation.
      */
     if (fifo_cnt == 1 && ent->flags & ESP_CMD_FLAG_RESIDUAL) {
         size_t count = 1;
         size_t offset = bytes_sent;
         u8 bval = esp_read8(ESP_FDATA);
 
         if (ent->flags & ESP_CMD_FLAG_AUTOSENSE)
             ent->sense_ptr[bytes_sent] = bval;
         else {
             struct esp_cmd_priv *p = ESP_CMD_PRIV(cmd);
             u8 *ptr;
 
             ptr = scsi_kmap_atomic_sg(p->cur_sg, p->num_sg,
                           &offset, &count);
             if (likely(ptr)) {
                 *(ptr + offset) = bval;
                 scsi_kunmap_atomic_sg(ptr);
             }
         }
         bytes_sent += fifo_cnt;
         ent->flags &= ~ESP_CMD_FLAG_RESIDUAL;
     }
     if (!(ent->flags & ESP_CMD_FLAG_WRITE))
         bytes_sent -= fifo_cnt;
 
     flush_fifo = 0;
     if (!esp->prev_soff) {
         /* Synchronous data transfer, always flush fifo. */
         flush_fifo = 1;
     } else {
         if (esp->rev == ESP100) {
             u32 fflags, phase;
 
             /* ESP100 has a chip bug where in the synchronous data
              * phase it can mistake a final long REQ pulse from the
              * target as an extra data byte.  Fun.
              *
              * To detect this case we resample the status register
              * and fifo flags.  If we're still in a data phase and
              * we see spurious chunks in the fifo, we return error
              * to the caller which should reset and set things up
              * such that we only try future transfers to this
              * target in synchronous mode.
              */
             esp->sreg = esp_read8(ESP_STATUS);
             phase = esp->sreg & ESP_STAT_PMASK;
             fflags = esp_read8(ESP_FFLAGS);
 
             if ((phase == ESP_DOP &&
                  (fflags & ESP_FF_ONOTZERO)) ||
                 (phase == ESP_DIP &&
                  (fflags & ESP_FF_FBYTES)))
                 return -1;
         }
         if (!(ent->flags & ESP_CMD_FLAG_WRITE))
             flush_fifo = 1;
     }
 
     if (flush_fifo)
         esp_flush_fifo(esp);
 
     return bytes_sent;
 }
 
 static void esp_setsync(struct esp *esp, struct esp_target_data *tp,
             u8 scsi_period, u8 scsi_offset,
             u8 esp_stp, u8 esp_soff)
 {
     spi_period(tp->starget) = scsi_period;
     spi_offset(tp->starget) = scsi_offset;
     spi_width(tp->starget) = (tp->flags & ESP_TGT_WIDE) ? 1 : 0;
 
     if (esp_soff) {
         esp_stp &= 0x1f;
         esp_soff |= esp->radelay;
         if (esp->rev >= FAS236) {
             u8 bit = ESP_CONFIG3_FSCSI;
             if (esp->rev >= FAS100A)
                 bit = ESP_CONFIG3_FAST;
 
             if (scsi_period < 50) {
                 if (esp->rev == FASHME)
                     esp_soff &= ~esp->radelay;
                 tp->esp_config3 |= bit;
             } else {
                 tp->esp_config3 &= ~bit;
             }
             esp->prev_cfg3 = tp->esp_config3;
             esp_write8(esp->prev_cfg3, ESP_CFG3);
         }
     }
 
     tp->esp_period = esp->prev_stp = esp_stp;
     tp->esp_offset = esp->prev_soff = esp_soff;
 
     esp_write8(esp_soff, ESP_SOFF);
     esp_write8(esp_stp, ESP_STP);
 
     tp->flags &= ~(ESP_TGT_NEGO_SYNC | ESP_TGT_CHECK_NEGO);
 
     spi_display_xfer_agreement(tp->starget);
 }
 
 static void esp_msgin_reject(struct esp *esp)
 {
     struct esp_cmd_entry *ent = esp->active_cmd;
     struct scsi_cmnd *cmd = ent->cmd;
     struct esp_target_data *tp;
     int tgt;
 
     tgt = cmd->device->id;
     tp = &esp->target[tgt];
 
     if (tp->flags & ESP_TGT_NEGO_WIDE) {
         tp->flags &= ~(ESP_TGT_NEGO_WIDE | ESP_TGT_WIDE);
 
         if (!esp_need_to_nego_sync(tp)) {
             tp->flags &= ~ESP_TGT_CHECK_NEGO;
             scsi_esp_cmd(esp, ESP_CMD_RATN);
         } else {
             esp->msg_out_len =
                 spi_populate_sync_msg(&esp->msg_out[0],
                               tp->nego_goal_period,
                               tp->nego_goal_offset);
             tp->flags |= ESP_TGT_NEGO_SYNC;
             scsi_esp_cmd(esp, ESP_CMD_SATN);
         }
         return;
     }
 
     if (tp->flags & ESP_TGT_NEGO_SYNC) {
         tp->flags &= ~(ESP_TGT_NEGO_SYNC | ESP_TGT_CHECK_NEGO);
         tp->esp_period = 0;
         tp->esp_offset = 0;
         esp_setsync(esp, tp, 0, 0, 0, 0);
         scsi_esp_cmd(esp, ESP_CMD_RATN);
         return;
     }
 
     shost_printk(KERN_INFO, esp->host, "Unexpected MESSAGE REJECT\n");
     esp_schedule_reset(esp);
 }
 
 static void esp_msgin_sdtr(struct esp *esp, struct esp_target_data *tp)
 {
     u8 period = esp->msg_in[3];
     u8 offset = esp->msg_in[4];
     u8 stp;
 
     if (!(tp->flags & ESP_TGT_NEGO_SYNC))
         goto do_reject;
 
     if (offset > 15)
         goto do_reject;
 
     if (offset) {
         int one_clock;
 
         if (period > esp->max_period) {
             period = offset = 0;
             goto do_sdtr;
         }
         if (period < esp->min_period)
             goto do_reject;
 
         one_clock = esp->ccycle / 1000;
         stp = DIV_ROUND_UP(period << 2, one_clock);
         if (stp && esp->rev >= FAS236) {
             if (stp >= 50)
                 stp--;
         }
     } else {
         stp = 0;
     }
 
     esp_setsync(esp, tp, period, offset, stp, offset);
     return;
 
 do_reject:
     esp->msg_out[0] = MESSAGE_REJECT;
     esp->msg_out_len = 1;
     scsi_esp_cmd(esp, ESP_CMD_SATN);
     return;
 
 do_sdtr:
     tp->nego_goal_period = period;
     tp->nego_goal_offset = offset;
     esp->msg_out_len =
         spi_populate_sync_msg(&esp->msg_out[0],
                       tp->nego_goal_period,
                       tp->nego_goal_offset);
     scsi_esp_cmd(esp, ESP_CMD_SATN);
 }
 
 static void esp_msgin_wdtr(struct esp *esp, struct esp_target_data *tp)
 {
     int size = 8 << esp->msg_in[3];
     u8 cfg3;
 
     if (esp->rev != FASHME)
         goto do_reject;
 
     if (size != 8 && size != 16)
         goto do_reject;
 
     if (!(tp->flags & ESP_TGT_NEGO_WIDE))
         goto do_reject;
 
     cfg3 = tp->esp_config3;
     if (size == 16) {
         tp->flags |= ESP_TGT_WIDE;
         cfg3 |= ESP_CONFIG3_EWIDE;
     } else {
         tp->flags &= ~ESP_TGT_WIDE;
         cfg3 &= ~ESP_CONFIG3_EWIDE;
     }
     tp->esp_config3 = cfg3;
     esp->prev_cfg3 = cfg3;
     esp_write8(cfg3, ESP_CFG3);
 
     tp->flags &= ~ESP_TGT_NEGO_WIDE;
 
     spi_period(tp->starget) = 0;
     spi_offset(tp->starget) = 0;
     if (!esp_need_to_nego_sync(tp)) {
         tp->flags &= ~ESP_TGT_CHECK_NEGO;
         scsi_esp_cmd(esp, ESP_CMD_RATN);
     } else {
         esp->msg_out_len =
             spi_populate_sync_msg(&esp->msg_out[0],
                           tp->nego_goal_period,
                           tp->nego_goal_offset);
         tp->flags |= ESP_TGT_NEGO_SYNC;
         scsi_esp_cmd(esp, ESP_CMD_SATN);
     }
     return;
 
 do_reject:
     esp->msg_out[0] = MESSAGE_REJECT;
     esp->msg_out_len = 1;
     scsi_esp_cmd(esp, ESP_CMD_SATN);
 }
 
 static void esp_msgin_extended(struct esp *esp)
 {
     struct esp_cmd_entry *ent = esp->active_cmd;
     struct scsi_cmnd *cmd = ent->cmd;
     struct esp_target_data *tp;
     int tgt = cmd->device->id;
 
     tp = &esp->target[tgt];
     if (esp->msg_in[2] == EXTENDED_SDTR) {
         esp_msgin_sdtr(esp, tp);
         return;
     }
     if (esp->msg_in[2] == EXTENDED_WDTR) {
         esp_msgin_wdtr(esp, tp);
         return;
     }
 
     shost_printk(KERN_INFO, esp->host,
              "Unexpected extended msg type %x\n", esp->msg_in[2]);
 
     esp->msg_out[0] = MESSAGE_REJECT;
     esp->msg_out_len = 1;
     scsi_esp_cmd(esp, ESP_CMD_SATN);
 }
 
 /* Analyze msgin bytes received from target so far.  Return non-zero
  * if there are more bytes needed to complete the message.
  */
 static int esp_msgin_process(struct esp *esp)
 {
     u8 msg0 = esp->msg_in[0];
     int len = esp->msg_in_len;
 
     if (msg0 & 0x80) {
         /* Identify */
         shost_printk(KERN_INFO, esp->host,
                  "Unexpected msgin identify\n");
         return 0;
     }
 
     switch (msg0) {
     case EXTENDED_MESSAGE:
         if (len == 1)
             return 1;
         if (len < esp->msg_in[1] + 2)
             return 1;
         esp_msgin_extended(esp);
         return 0;
 
     case IGNORE_WIDE_RESIDUE: {
         struct esp_cmd_entry *ent;
         struct esp_cmd_priv *spriv;
         if (len == 1)
             return 1;
 
         if (esp->msg_in[1] != 1)
             goto do_reject;
 
         ent = esp->active_cmd;
         spriv = ESP_CMD_PRIV(ent->cmd);
 
         if (spriv->cur_residue == sg_dma_len(spriv->cur_sg)) {
             spriv->cur_sg = spriv->prv_sg;
             spriv->cur_residue = 1;
         } else
             spriv->cur_residue++;
         spriv->tot_residue++;
         return 0;
     }
     case NOP:
         return 0;
     case RESTORE_POINTERS:
         esp_restore_pointers(esp, esp->active_cmd);
         return 0;
     case SAVE_POINTERS:
         esp_save_pointers(esp, esp->active_cmd);
         return 0;
 
     case COMMAND_COMPLETE:
     case DISCONNECT: {
         struct esp_cmd_entry *ent = esp->active_cmd;
 
         ent->message = msg0;
         esp_event(esp, ESP_EVENT_FREE_BUS);
         esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
         return 0;
     }
     case MESSAGE_REJECT:
         esp_msgin_reject(esp);
         return 0;
 
     default:
     do_reject:
         esp->msg_out[0] = MESSAGE_REJECT;
         esp->msg_out_len = 1;
         scsi_esp_cmd(esp, ESP_CMD_SATN);
         return 0;
     }
 }
 
 static int esp_process_event(struct esp *esp)
 {
     int write, i;
 
 again:
     write = 0;
     esp_log_event("process event %d phase %x\n",
               esp->event, esp->sreg & ESP_STAT_PMASK);
     switch (esp->event) {
     case ESP_EVENT_CHECK_PHASE:
         switch (esp->sreg & ESP_STAT_PMASK) {
         case ESP_DOP:
             esp_event(esp, ESP_EVENT_DATA_OUT);
             break;
         case ESP_DIP:
             esp_event(esp, ESP_EVENT_DATA_IN);
             break;
         case ESP_STATP:
             esp_flush_fifo(esp);
             scsi_esp_cmd(esp, ESP_CMD_ICCSEQ);
             esp_event(esp, ESP_EVENT_STATUS);
             esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
             return 1;
 
         case ESP_MOP:
             esp_event(esp, ESP_EVENT_MSGOUT);
             break;
 
         case ESP_MIP:
             esp_event(esp, ESP_EVENT_MSGIN);
             break;
 
         case ESP_CMDP:
             esp_event(esp, ESP_EVENT_CMD_START);
             break;
 
         default:
             shost_printk(KERN_INFO, esp->host,
                      "Unexpected phase, sreg=%02x\n",
                      esp->sreg);
             esp_schedule_reset(esp);
             return 0;
         }
         goto again;
 
     case ESP_EVENT_DATA_IN:
         write = 1;
         fallthrough;
 
     case ESP_EVENT_DATA_OUT: {
         struct esp_cmd_entry *ent = esp->active_cmd;
         struct scsi_cmnd *cmd = ent->cmd;
         dma_addr_t dma_addr = esp_cur_dma_addr(ent, cmd);
         unsigned int dma_len = esp_cur_dma_len(ent, cmd);
 
         if (esp->rev == ESP100)
             scsi_esp_cmd(esp, ESP_CMD_NULL);
 
         if (write)
             ent->flags |= ESP_CMD_FLAG_WRITE;
         else
             ent->flags &= ~ESP_CMD_FLAG_WRITE;
 
         if (esp->ops->dma_length_limit)
             dma_len = esp->ops->dma_length_limit(esp, dma_addr,
                                  dma_len);
         else
             dma_len = esp_dma_length_limit(esp, dma_addr, dma_len);
 
         esp->data_dma_len = dma_len;
 
         if (!dma_len) {
             shost_printk(KERN_ERR, esp->host,
                      "DMA length is zero!\n");
             shost_printk(KERN_ERR, esp->host,
                      "cur adr[%08llx] len[%08x]\n",
                      (unsigned long long)esp_cur_dma_addr(ent, cmd),
                      esp_cur_dma_len(ent, cmd));
             esp_schedule_reset(esp);
             return 0;
         }
 
         esp_log_datastart("start data addr[%08llx] len[%u] write(%d)\n",
                   (unsigned long long)dma_addr, dma_len, write);
 
         esp->ops->send_dma_cmd(esp, dma_addr, dma_len, dma_len,
                        write, ESP_CMD_DMA | ESP_CMD_TI);
         esp_event(esp, ESP_EVENT_DATA_DONE);
         break;
     }
     case ESP_EVENT_DATA_DONE: {
         struct esp_cmd_entry *ent = esp->active_cmd;
         struct scsi_cmnd *cmd = ent->cmd;
         int bytes_sent;
 
         if (esp->ops->dma_error(esp)) {
             shost_printk(KERN_INFO, esp->host,
                      "data done, DMA error, resetting\n");
             esp_schedule_reset(esp);
             return 0;
         }
 
         if (ent->flags & ESP_CMD_FLAG_WRITE) {
             /* XXX parity errors, etc. XXX */
 
             esp->ops->dma_drain(esp);
         }
         esp->ops->dma_invalidate(esp);
 
         if (esp->ireg != ESP_INTR_BSERV) {
             /* We should always see exactly a bus-service
              * interrupt at the end of a successful transfer.
              */
             shost_printk(KERN_INFO, esp->host,
                      "data done, not BSERV, resetting\n");
             esp_schedule_reset(esp);
             return 0;
         }
 
         bytes_sent = esp_data_bytes_sent(esp, ent, cmd);
 
         esp_log_datadone("data done flgs[%x] sent[%d]\n",
                  ent->flags, bytes_sent);
 
         if (bytes_sent < 0) {
             /* XXX force sync mode for this target XXX */
             esp_schedule_reset(esp);
             return 0;
         }
 
         esp_advance_dma(esp, ent, cmd, bytes_sent);
         esp_event(esp, ESP_EVENT_CHECK_PHASE);
         goto again;
     }
 
     case ESP_EVENT_STATUS: {
         struct esp_cmd_entry *ent = esp->active_cmd;
 
         if (esp->ireg & ESP_INTR_FDONE) {
             ent->status = esp_read8(ESP_FDATA);
             ent->message = esp_read8(ESP_FDATA);
             scsi_esp_cmd(esp, ESP_CMD_MOK);
         } else if (esp->ireg == ESP_INTR_BSERV) {
             ent->status = esp_read8(ESP_FDATA);
             ent->message = 0xff;
             esp_event(esp, ESP_EVENT_MSGIN);
             return 0;
         }
 
         if (ent->message != COMMAND_COMPLETE) {
             shost_printk(KERN_INFO, esp->host,
                      "Unexpected message %x in status\n",
                      ent->message);
             esp_schedule_reset(esp);
             return 0;
         }
 
         esp_event(esp, ESP_EVENT_FREE_BUS);
         esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
         break;
     }
     case ESP_EVENT_FREE_BUS: {
         struct esp_cmd_entry *ent = esp->active_cmd;
         struct scsi_cmnd *cmd = ent->cmd;
 
         if (ent->message == COMMAND_COMPLETE ||
             ent->message == DISCONNECT)
             scsi_esp_cmd(esp, ESP_CMD_ESEL);
 
         if (ent->message == COMMAND_COMPLETE) {
             esp_log_cmddone("Command done status[%x] message[%x]\n",
                     ent->status, ent->message);
             if (ent->status == SAM_STAT_TASK_SET_FULL)
                 esp_event_queue_full(esp, ent);
 
             if (ent->status == SAM_STAT_CHECK_CONDITION &&
                 !(ent->flags & ESP_CMD_FLAG_AUTOSENSE)) {
                 ent->flags |= ESP_CMD_FLAG_AUTOSENSE;
                 esp_autosense(esp, ent);
             } else {
                 esp_cmd_is_done(esp, ent, cmd, DID_OK);
             }
         } else if (ent->message == DISCONNECT) {
             esp_log_disconnect("Disconnecting tgt[%d] tag[%x:%x]\n",
                        cmd->device->id,
                        ent->tag[0], ent->tag[1]);
 
             esp->active_cmd = NULL;
             esp_maybe_execute_command(esp);
         } else {
             shost_printk(KERN_INFO, esp->host,
                      "Unexpected message %x in freebus\n",
                      ent->message);
             esp_schedule_reset(esp);
             return 0;
         }
         if (esp->active_cmd)
             esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
         break;
     }
     case ESP_EVENT_MSGOUT: {
         scsi_esp_cmd(esp, ESP_CMD_FLUSH);
 
         if (esp_debug & ESP_DEBUG_MSGOUT) {
             int i;
             printk("ESP: Sending message [ ");
             for (i = 0; i < esp->msg_out_len; i++)
                 printk("%02x ", esp->msg_out[i]);
             printk("]\n");
         }
 
         if (esp->rev == FASHME) {
             int i;
 
             /* Always use the fifo.  */
             for (i = 0; i < esp->msg_out_len; i++) {
                 esp_write8(esp->msg_out[i], ESP_FDATA);
                 esp_write8(0, ESP_FDATA);
             }
             scsi_esp_cmd(esp, ESP_CMD_TI);
         } else {
             if (esp->msg_out_len == 1) {
                 esp_write8(esp->msg_out[0], ESP_FDATA);
                 scsi_esp_cmd(esp, ESP_CMD_TI);
             } else if (esp->flags & ESP_FLAG_USE_FIFO) {
                 for (i = 0; i < esp->msg_out_len; i++)
                     esp_write8(esp->msg_out[i], ESP_FDATA);
                 scsi_esp_cmd(esp, ESP_CMD_TI);
             } else {
                 /* Use DMA. */
                 memcpy(esp->command_block,
                        esp->msg_out,
                        esp->msg_out_len);
 
                 esp->ops->send_dma_cmd(esp,
                                esp->command_block_dma,
                                esp->msg_out_len,
                                esp->msg_out_len,
                                0,
                                ESP_CMD_DMA|ESP_CMD_TI);
             }
         }
         esp_event(esp, ESP_EVENT_MSGOUT_DONE);
         break;
     }
     case ESP_EVENT_MSGOUT_DONE:
         if (esp->rev == FASHME) {
             scsi_esp_cmd(esp, ESP_CMD_FLUSH);
         } else {
             if (esp->msg_out_len > 1)
                 esp->ops->dma_invalidate(esp);
 
             /* XXX if the chip went into disconnected mode,
              * we can't run the phase state machine anyway.
              */
             if (!(esp->ireg & ESP_INTR_DC))
                 scsi_esp_cmd(esp, ESP_CMD_NULL);
         }
 
         esp->msg_out_len = 0;
 
         esp_event(esp, ESP_EVENT_CHECK_PHASE);
         goto again;
     case ESP_EVENT_MSGIN:
         if (esp->ireg & ESP_INTR_BSERV) {
             if (esp->rev == FASHME) {
                 if (!(esp_read8(ESP_STATUS2) &
                       ESP_STAT2_FEMPTY))
                     scsi_esp_cmd(esp, ESP_CMD_FLUSH);
             } else {
                 scsi_esp_cmd(esp, ESP_CMD_FLUSH);
                 if (esp->rev == ESP100)
                     scsi_esp_cmd(esp, ESP_CMD_NULL);
             }
             scsi_esp_cmd(esp, ESP_CMD_TI);
             esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
             return 1;
         }
         if (esp->ireg & ESP_INTR_FDONE) {
             u8 val;
 
             if (esp->rev == FASHME)
                 val = esp->fifo[0];
             else
                 val = esp_read8(ESP_FDATA);
             esp->msg_in[esp->msg_in_len++] = val;
 
             esp_log_msgin("Got msgin byte %x\n", val);
 
             if (!esp_msgin_process(esp))
                 esp->msg_in_len = 0;
 
             if (esp->rev == FASHME)
                 scsi_esp_cmd(esp, ESP_CMD_FLUSH);
 
             scsi_esp_cmd(esp, ESP_CMD_MOK);
 
             /* Check whether a bus reset is to be done next */
             if (esp->event == ESP_EVENT_RESET)
                 return 0;
 
             if (esp->event != ESP_EVENT_FREE_BUS)
                 esp_event(esp, ESP_EVENT_CHECK_PHASE);
         } else {
             shost_printk(KERN_INFO, esp->host,
                      "MSGIN neither BSERV not FDON, resetting");
             esp_schedule_reset(esp);
             return 0;
         }
         break;
     case ESP_EVENT_CMD_START:
         memcpy(esp->command_block, esp->cmd_bytes_ptr,
                esp->cmd_bytes_left);
         esp_send_dma_cmd(esp, esp->cmd_bytes_left, 16, ESP_CMD_TI);
         esp_event(esp, ESP_EVENT_CMD_DONE);
         esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
         break;
     case ESP_EVENT_CMD_DONE:
         esp->ops->dma_invalidate(esp);
         if (esp->ireg & ESP_INTR_BSERV) {
             esp_event(esp, ESP_EVENT_CHECK_PHASE);
             goto again;
         }
         esp_schedule_reset(esp);
         return 0;
 
     case ESP_EVENT_RESET:
         scsi_esp_cmd(esp, ESP_CMD_RS);
         break;
 
     default:
         shost_printk(KERN_INFO, esp->host,
                  "Unexpected event %x, resetting\n", esp->event);
         esp_schedule_reset(esp);
         return 0;
     }
     return 1;
 }
 
 static void esp_reset_cleanup_one(struct esp *esp, struct esp_cmd_entry *ent)
 {
     struct scsi_cmnd *cmd = ent->cmd;
 
     esp_unmap_dma(esp, cmd);
     esp_free_lun_tag(ent, cmd->device->hostdata);
     cmd->result = DID_RESET << 16;
 
     if (ent->flags & ESP_CMD_FLAG_AUTOSENSE)
         esp_unmap_sense(esp, ent);
 
     scsi_done(cmd);
     list_del(&ent->list);
     esp_put_ent(esp, ent);
 }
 
 static void esp_clear_hold(struct scsi_device *dev, void *data)
 {
     struct esp_lun_data *lp = dev->hostdata;
 
     BUG_ON(lp->num_tagged);
     lp->hold = 0;
 }
 
 static void esp_reset_cleanup(struct esp *esp)
 {
     struct esp_cmd_entry *ent, *tmp;
     int i;
 
     list_for_each_entry_safe(ent, tmp, &esp->queued_cmds, list) {
         struct scsi_cmnd *cmd = ent->cmd;
 
         list_del(&ent->list);
         cmd->result = DID_RESET << 16;
         scsi_done(cmd);
         esp_put_ent(esp, ent);
     }
 
     list_for_each_entry_safe(ent, tmp, &esp->active_cmds, list) {
         if (ent == esp->active_cmd)
             esp->active_cmd = NULL;
         esp_reset_cleanup_one(esp, ent);
     }
 
     BUG_ON(esp->active_cmd != NULL);
 
     /* Force renegotiation of sync/wide transfers.  */
     for (i = 0; i < ESP_MAX_TARGET; i++) {
         struct esp_target_data *tp = &esp->target[i];
 
         tp->esp_period = 0;
         tp->esp_offset = 0;
         tp->esp_config3 &= ~(ESP_CONFIG3_EWIDE |
                      ESP_CONFIG3_FSCSI |
                      ESP_CONFIG3_FAST);
         tp->flags &= ~ESP_TGT_WIDE;
         tp->flags |= ESP_TGT_CHECK_NEGO;
 
         if (tp->starget)
             __starget_for_each_device(tp->starget, NULL,
                           esp_clear_hold);
     }
     esp->flags &= ~ESP_FLAG_RESETTING;
 }
 
 /* Runs under host->lock */
 static void __esp_interrupt(struct esp *esp)
 {
     int finish_reset, intr_done;
     u8 phase;
 
        /*
     * Once INTRPT is read STATUS and SSTEP are cleared.
     */
     esp->sreg = esp_read8(ESP_STATUS);
     esp->seqreg = esp_read8(ESP_SSTEP);
     esp->ireg = esp_read8(ESP_INTRPT);
 
     if (esp->flags & ESP_FLAG_RESETTING) {
         finish_reset = 1;
     } else {
         if (esp_check_gross_error(esp))
             return;
 
         finish_reset = esp_check_spur_intr(esp);
         if (finish_reset < 0)
             return;
     }
 
     if (esp->ireg & ESP_INTR_SR)
         finish_reset = 1;
 
     if (finish_reset) {
         esp_reset_cleanup(esp);
         if (esp->eh_reset) {
             complete(esp->eh_reset);
             esp->eh_reset = NULL;
         }
         return;
     }
 
     phase = (esp->sreg & ESP_STAT_PMASK);
     if (esp->rev == FASHME) {
         if (((phase != ESP_DIP && phase != ESP_DOP) &&
              esp->select_state == ESP_SELECT_NONE &&
              esp->event != ESP_EVENT_STATUS &&
              esp->event != ESP_EVENT_DATA_DONE) ||
             (esp->ireg & ESP_INTR_RSEL)) {
             esp->sreg2 = esp_read8(ESP_STATUS2);
             if (!(esp->sreg2 & ESP_STAT2_FEMPTY) ||
                 (esp->sreg2 & ESP_STAT2_F1BYTE))
                 hme_read_fifo(esp);
         }
     }
 
     esp_log_intr("intr sreg[%02x] seqreg[%02x] "
              "sreg2[%02x] ireg[%02x]\n",
              esp->sreg, esp->seqreg, esp->sreg2, esp->ireg);
 
     intr_done = 0;
 
     if (esp->ireg & (ESP_INTR_S | ESP_INTR_SATN | ESP_INTR_IC)) {
         shost_printk(KERN_INFO, esp->host,
                  "unexpected IREG %02x\n", esp->ireg);
         if (esp->ireg & ESP_INTR_IC)
             esp_dump_cmd_log(esp);
 
         esp_schedule_reset(esp);
     } else {
         if (esp->ireg & ESP_INTR_RSEL) {
             if (esp->active_cmd)
                 (void) esp_finish_select(esp);
             intr_done = esp_reconnect(esp);
         } else {
             /* Some combination of FDONE, BSERV, DC. */
             if (esp->select_state != ESP_SELECT_NONE)
                 intr_done = esp_finish_select(esp);
         }
     }
     while (!intr_done)
         intr_done = esp_process_event(esp);
 }
 
 irqreturn_t scsi_esp_intr(int irq, void *dev_id)
 {
     struct esp *esp = dev_id;
     unsigned long flags;
     irqreturn_t ret;
 
     spin_lock_irqsave(esp->host->host_lock, flags);
     ret = IRQ_NONE;
     if (esp->ops->irq_pending(esp)) {
         ret = IRQ_HANDLED;
         for (;;) {
             int i;
 
             __esp_interrupt(esp);
             if (!(esp->flags & ESP_FLAG_QUICKIRQ_CHECK))
                 break;
             esp->flags &= ~ESP_FLAG_QUICKIRQ_CHECK;
 
             for (i = 0; i < ESP_QUICKIRQ_LIMIT; i++) {
                 if (esp->ops->irq_pending(esp))
                     break;
             }
             if (i == ESP_QUICKIRQ_LIMIT)
                 break;
         }
     }
     spin_unlock_irqrestore(esp->host->host_lock, flags);
 
     return ret;
 }
 EXPORT_SYMBOL(scsi_esp_intr);
 
 static void esp_get_revision(struct esp *esp)
 {
     u8 val;
 
     esp->config1 = (ESP_CONFIG1_PENABLE | (esp->scsi_id & 7));
     if (esp->config2 == 0) {
         esp->config2 = (ESP_CONFIG2_SCSI2ENAB | ESP_CONFIG2_REGPARITY);
         esp_write8(esp->config2, ESP_CFG2);
 
         val = esp_read8(ESP_CFG2);
         val &= ~ESP_CONFIG2_MAGIC;
 
         esp->config2 = 0;
         if (val != (ESP_CONFIG2_SCSI2ENAB | ESP_CONFIG2_REGPARITY)) {
             /*
              * If what we write to cfg2 does not come back,
              * cfg2 is not implemented.
              * Therefore this must be a plain esp100.
              */
             esp->rev = ESP100;
             return;
         }
     }
 
     esp_set_all_config3(esp, 5);
     esp->prev_cfg3 = 5;
     esp_write8(esp->config2, ESP_CFG2);
     esp_write8(0, ESP_CFG3);
     esp_write8(esp->prev_cfg3, ESP_CFG3);
 
     val = esp_read8(ESP_CFG3);
     if (val != 5) {
         /* The cfg2 register is implemented, however
          * cfg3 is not, must be esp100a.
          */
         esp->rev = ESP100A;
     } else {
         esp_set_all_config3(esp, 0);
         esp->prev_cfg3 = 0;
         esp_write8(esp->prev_cfg3, ESP_CFG3);
 
         /* All of cfg{1,2,3} implemented, must be one of
          * the fas variants, figure out which one.
          */
         if (esp->cfact == 0 || esp->cfact > ESP_CCF_F5) {
             esp->rev = FAST;
             esp->sync_defp = SYNC_DEFP_FAST;
         } else {
             esp->rev = ESP236;
         }
     }
 }
 
 static void esp_init_swstate(struct esp *esp)
 {
     int i;
 
     INIT_LIST_HEAD(&esp->queued_cmds);
     INIT_LIST_HEAD(&esp->active_cmds);
     INIT_LIST_HEAD(&esp->esp_cmd_pool);
 
     /* Start with a clear state, domain validation (via ->slave_configure,
      * spi_dv_device()) will attempt to enable SYNC, WIDE, and tagged
      * commands.
      */
     for (i = 0 ; i < ESP_MAX_TARGET; i++) {
         esp->target[i].flags = 0;
         esp->target[i].nego_goal_period = 0;
         esp->target[i].nego_goal_offset = 0;
         esp->target[i].nego_goal_width = 0;
         esp->target[i].nego_goal_tags = 0;
     }
 }
 
 /* This places the ESP into a known state at boot time. */
 static void esp_bootup_reset(struct esp *esp)
 {
     u8 val;
 
     /* Reset the DMA */
     esp->ops->reset_dma(esp);
 
     /* Reset the ESP */
     esp_reset_esp(esp);
 
     /* Reset the SCSI bus, but tell ESP not to generate an irq */
     val = esp_read8(ESP_CFG1);
     val |= ESP_CONFIG1_SRRDISAB;
     esp_write8(val, ESP_CFG1);
 
     scsi_esp_cmd(esp, ESP_CMD_RS);
     udelay(400);
 
     esp_write8(esp->config1, ESP_CFG1);
 
     /* Eat any bitrot in the chip and we are done... */
     esp_read8(ESP_INTRPT);
 }
 
 static void esp_set_clock_params(struct esp *esp)
 {
     int fhz;
     u8 ccf;
 
     /* This is getting messy but it has to be done correctly or else
      * you get weird behavior all over the place.  We are trying to
      * basically figure out three pieces of information.
      *
      * a) Clock Conversion Factor
      *
      *    This is a representation of the input crystal clock frequency
      *    going into the ESP on this machine.  Any operation whose timing
      *    is longer than 400ns depends on this value being correct.  For
      *    example, you'll get blips for arbitration/selection during high
      *    load or with multiple targets if this is not set correctly.
      *
      * b) Selection Time-Out
      *
      *    The ESP isn't very bright and will arbitrate for the bus and try
      *    to select a target forever if you let it.  This value tells the
      *    ESP when it has taken too long to negotiate and that it should
      *    interrupt the CPU so we can see what happened.  The value is
      *    computed as follows (from NCR/Symbios chip docs).
      *
      *          (Time Out Period) *  (Input Clock)
      *    STO = ----------------------------------
      *          (8192) * (Clock Conversion Factor)
      *
      *    We use a time out period of 250ms (ESP_BUS_TIMEOUT).
      *
      * c) Imperical constants for synchronous offset and transfer period
          *    register values
      *
      *    This entails the smallest and largest sync period we could ever
      *    handle on this ESP.
      */
     fhz = esp->cfreq;
 
     ccf = ((fhz / 1000000) + 4) / 5;
     if (ccf == 1)
         ccf = 2;
 
     /* If we can't find anything reasonable, just assume 20MHZ.
      * This is the clock frequency of the older sun4c's where I've
      * been unable to find the clock-frequency PROM property.  All
      * other machines provide useful values it seems.
      */
     if (fhz <= 5000000 || ccf < 1 || ccf > 8) {
         fhz = 20000000;
         ccf = 4;
     }
 
     esp->cfact = (ccf == 8 ? 0 : ccf);
     esp->cfreq = fhz;
     esp->ccycle = ESP_HZ_TO_CYCLE(fhz);
     esp->ctick = ESP_TICK(ccf, esp->ccycle);
     esp->neg_defp = ESP_NEG_DEFP(fhz, ccf);
     esp->sync_defp = SYNC_DEFP_SLOW;
 }
 
 static const char *esp_chip_names[] = {
     "ESP100",
     "ESP100A",
     "ESP236",
     "FAS236",
     "AM53C974",
     "53CF9x-2",
     "FAS100A",
     "FAST",
     "FASHME",
 };
 
 static struct scsi_transport_template *esp_transport_template;
 
 int scsi_esp_register(struct esp *esp)
 {
     static int instance;
     int err;
 
     if (!esp->num_tags)
         esp->num_tags = ESP_DEFAULT_TAGS;
     esp->host->transportt = esp_transport_template;
     esp->host->max_lun = ESP_MAX_LUN;
     esp->host->cmd_per_lun = 2;
     esp->host->unique_id = instance;
 
     esp_set_clock_params(esp);
 
     esp_get_revision(esp);
 
     esp_init_swstate(esp);
 
     esp_bootup_reset(esp);
 
     dev_printk(KERN_INFO, esp->dev, "esp%u: regs[%1p:%1p] irq[%u]\n",
            esp->host->unique_id, esp->regs, esp->dma_regs,
            esp->host->irq);
     dev_printk(KERN_INFO, esp->dev,
            "esp%u: is a %s, %u MHz (ccf=%u), SCSI ID %u\n",
            esp->host->unique_id, esp_chip_names[esp->rev],
            esp->cfreq / 1000000, esp->cfact, esp->scsi_id);
 
     /* Let the SCSI bus reset settle. */
     ssleep(esp_bus_reset_settle);
 
     err = scsi_add_host(esp->host, esp->dev);
     if (err)
         return err;
 
     instance++;
 
     scsi_scan_host(esp->host);
 
     return 0;
 }
 EXPORT_SYMBOL(scsi_esp_register);
 
 void scsi_esp_unregister(struct esp *esp)
 {
     scsi_remove_host(esp->host);
 }
 EXPORT_SYMBOL(scsi_esp_unregister);
 
 static int esp_target_alloc(struct scsi_target *starget)
 {
     struct esp *esp = shost_priv(dev_to_shost(&starget->dev));
     struct esp_target_data *tp = &esp->target[starget->id];
 
     tp->starget = starget;
 
     return 0;
 }
 
 static void esp_target_destroy(struct scsi_target *starget)
 {
     struct esp *esp = shost_priv(dev_to_shost(&starget->dev));
     struct esp_target_data *tp = &esp->target[starget->id];
 
     tp->starget = NULL;
 }
 
 static int esp_slave_alloc(struct scsi_device *dev)
 {
     struct esp *esp = shost_priv(dev->host);
     struct esp_target_data *tp = &esp->target[dev->id];
     struct esp_lun_data *lp;
 
     lp = kzalloc(sizeof(*lp), GFP_KERNEL);
     if (!lp)
         return -ENOMEM;
     dev->hostdata = lp;
 
     spi_min_period(tp->starget) = esp->min_period;
     spi_max_offset(tp->starget) = 15;
 
     if (esp->flags & ESP_FLAG_WIDE_CAPABLE)
         spi_max_width(tp->starget) = 1;
     else
         spi_max_width(tp->starget) = 0;
 
     return 0;
 }
 
 static int esp_slave_configure(struct scsi_device *dev)
 {
     struct esp *esp = shost_priv(dev->host);
     struct esp_target_data *tp = &esp->target[dev->id];
 
     if (dev->tagged_supported)
         scsi_change_queue_depth(dev, esp->num_tags);
 
     tp->flags |= ESP_TGT_DISCONNECT;
 
     if (!spi_initial_dv(dev->sdev_target))
         spi_dv_device(dev);
 
     return 0;
 }
 
 static void esp_slave_destroy(struct scsi_device *dev)
 {
     struct esp_lun_data *lp = dev->hostdata;
 
     kfree(lp);
     dev->hostdata = NULL;
 }
 
 static int esp_eh_abort_handler(struct scsi_cmnd *cmd)
 {
     struct esp *esp = shost_priv(cmd->device->host);
     struct esp_cmd_entry *ent, *tmp;
     struct completion eh_done;
     unsigned long flags;
 
     /* XXX This helps a lot with debugging but might be a bit
      * XXX much for the final driver.
      */
     spin_lock_irqsave(esp->host->host_lock, flags);
     shost_printk(KERN_ERR, esp->host, "Aborting command [%p:%02x]\n",
              cmd, cmd->cmnd[0]);
     ent = esp->active_cmd;
     if (ent)
         shost_printk(KERN_ERR, esp->host,
                  "Current command [%p:%02x]\n",
                  ent->cmd, ent->cmd->cmnd[0]);
     list_for_each_entry(ent, &esp->queued_cmds, list) {
         shost_printk(KERN_ERR, esp->host, "Queued command [%p:%02x]\n",
                  ent->cmd, ent->cmd->cmnd[0]);
     }
     list_for_each_entry(ent, &esp->active_cmds, list) {
         shost_printk(KERN_ERR, esp->host, " Active command [%p:%02x]\n",
                  ent->cmd, ent->cmd->cmnd[0]);
     }
     esp_dump_cmd_log(esp);
     spin_unlock_irqrestore(esp->host->host_lock, flags);
 
     spin_lock_irqsave(esp->host->host_lock, flags);
 
     ent = NULL;
     list_for_each_entry(tmp, &esp->queued_cmds, list) {
         if (tmp->cmd == cmd) {
             ent = tmp;
             break;
         }
     }
 
     if (ent) {
         /* Easiest case, we didn't even issue the command
          * yet so it is trivial to abort.
          */
         list_del(&ent->list);
 
         cmd->result = DID_ABORT << 16;
         scsi_done(cmd);
 
         esp_put_ent(esp, ent);
 
         goto out_success;
     }
 
     init_completion(&eh_done);
 
     ent = esp->active_cmd;
     if (ent && ent->cmd == cmd) {
         /* Command is the currently active command on
          * the bus.  If we already have an output message
          * pending, no dice.
          */
         if (esp->msg_out_len)
             goto out_failure;
 
         /* Send out an abort, encouraging the target to
          * go to MSGOUT phase by asserting ATN.
          */
         esp->msg_out[0] = ABORT_TASK_SET;
         esp->msg_out_len = 1;
         ent->eh_done = &eh_done;
 
         scsi_esp_cmd(esp, ESP_CMD_SATN);
     } else {
         /* The command is disconnected.  This is not easy to
          * abort.  For now we fail and let the scsi error
          * handling layer go try a scsi bus reset or host
          * reset.
          *
          * What we could do is put together a scsi command
          * solely for the purpose of sending an abort message
          * to the target.  Coming up with all the code to
          * cook up scsi commands, special case them everywhere,
          * etc. is for questionable gain and it would be better
          * if the generic scsi error handling layer could do at
          * least some of that for us.
          *
          * Anyways this is an area for potential future improvement
          * in this driver.
          */
         goto out_failure;
     }
 
     spin_unlock_irqrestore(esp->host->host_lock, flags);
 
     if (!wait_for_completion_timeout(&eh_done, 5 * HZ)) {
         spin_lock_irqsave(esp->host->host_lock, flags);
         ent->eh_done = NULL;
         spin_unlock_irqrestore(esp->host->host_lock, flags);
 
         return FAILED;
     }
 
     return SUCCESS;
 
 out_success:
     spin_unlock_irqrestore(esp->host->host_lock, flags);
     return SUCCESS;
 
 out_failure:
     /* XXX This might be a good location to set ESP_TGT_BROKEN
      * XXX since we know which target/lun in particular is
      * XXX causing trouble.
      */
     spin_unlock_irqrestore(esp->host->host_lock, flags);
     return FAILED;
 }
 
 static int esp_eh_bus_reset_handler(struct scsi_cmnd *cmd)
 {
     struct esp *esp = shost_priv(cmd->device->host);
     struct completion eh_reset;
     unsigned long flags;
 
     init_completion(&eh_reset);
 
     spin_lock_irqsave(esp->host->host_lock, flags);
 
     esp->eh_reset = &eh_reset;
 
     /* XXX This is too simple... We should add lots of
      * XXX checks here so that if we find that the chip is
      * XXX very wedged we return failure immediately so
      * XXX that we can perform a full chip reset.
      */
     esp->flags |= ESP_FLAG_RESETTING;
     scsi_esp_cmd(esp, ESP_CMD_RS);
 
     spin_unlock_irqrestore(esp->host->host_lock, flags);
 
     ssleep(esp_bus_reset_settle);
 
     if (!wait_for_completion_timeout(&eh_reset, 5 * HZ)) {
         spin_lock_irqsave(esp->host->host_lock, flags);
         esp->eh_reset = NULL;
         spin_unlock_irqrestore(esp->host->host_lock, flags);
 
         return FAILED;
     }
 
     return SUCCESS;
 }
 
 /* All bets are off, reset the entire device.  */
 static int esp_eh_host_reset_handler(struct scsi_cmnd *cmd)
 {
     struct esp *esp = shost_priv(cmd->device->host);
     unsigned long flags;
 
     spin_lock_irqsave(esp->host->host_lock, flags);
     esp_bootup_reset(esp);
     esp_reset_cleanup(esp);
     spin_unlock_irqrestore(esp->host->host_lock, flags);
 
     ssleep(esp_bus_reset_settle);
 
     return SUCCESS;
 }
 
 static const char *esp_info(struct Scsi_Host *host)
 {
     return "esp";
 }
 
 struct scsi_host_template scsi_esp_template = {
     .module         = THIS_MODULE,
     .name           = "esp",
     .info           = esp_info,
     .queuecommand       = esp_queuecommand,
     .target_alloc       = esp_target_alloc,
     .target_destroy     = esp_target_destroy,
     .slave_alloc        = esp_slave_alloc,
     .slave_configure    = esp_slave_configure,
     .slave_destroy      = esp_slave_destroy,
     .eh_abort_handler   = esp_eh_abort_handler,
     .eh_bus_reset_handler   = esp_eh_bus_reset_handler,
     .eh_host_reset_handler  = esp_eh_host_reset_handler,
     .can_queue      = 7,
     .this_id        = 7,
     .sg_tablesize       = SG_ALL,
     .max_sectors        = 0xffff,
     .skip_settle_delay  = 1,
     .cmd_size       = sizeof(struct esp_cmd_priv),
 };
 EXPORT_SYMBOL(scsi_esp_template);
 
 static void esp_get_signalling(struct Scsi_Host *host)
 {
     struct esp *esp = shost_priv(host);
     enum spi_signal_type type;
 
     if (esp->flags & ESP_FLAG_DIFFERENTIAL)
         type = SPI_SIGNAL_HVD;
     else
         type = SPI_SIGNAL_SE;
 
     spi_signalling(host) = type;
 }
 
 static void esp_set_offset(struct scsi_target *target, int offset)
 {
     struct Scsi_Host *host = dev_to_shost(target->dev.parent);
     struct esp *esp = shost_priv(host);
     struct esp_target_data *tp = &esp->target[target->id];
 
     if (esp->flags & ESP_FLAG_DISABLE_SYNC)
         tp->nego_goal_offset = 0;
     else
         tp->nego_goal_offset = offset;
     tp->flags |= ESP_TGT_CHECK_NEGO;
 }
 
 static void esp_set_period(struct scsi_target *target, int period)
 {
     struct Scsi_Host *host = dev_to_shost(target->dev.parent);
     struct esp *esp = shost_priv(host);
     struct esp_target_data *tp = &esp->target[target->id];
 
     tp->nego_goal_period = period;
     tp->flags |= ESP_TGT_CHECK_NEGO;
 }
 
 static void esp_set_width(struct scsi_target *target, int width)
 {
     struct Scsi_Host *host = dev_to_shost(target->dev.parent);
     struct esp *esp = shost_priv(host);
     struct esp_target_data *tp = &esp->target[target->id];
 
     tp->nego_goal_width = (width ? 1 : 0);
     tp->flags |= ESP_TGT_CHECK_NEGO;
 }
 
 static struct spi_function_template esp_transport_ops = {
     .set_offset     = esp_set_offset,
     .show_offset        = 1,
     .set_period     = esp_set_period,
     .show_period        = 1,
     .set_width      = esp_set_width,
     .show_width     = 1,
     .get_signalling     = esp_get_signalling,
 };
 
 static int __init esp_init(void)
 {
     esp_transport_template = spi_attach_transport(&esp_transport_ops);
     if (!esp_transport_template)
         return -ENODEV;
 
     return 0;
 }
 
 static void __exit esp_exit(void)
 {
     spi_release_transport(esp_transport_template);
 }
 
 MODULE_DESCRIPTION("ESP SCSI driver core");
 MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(DRV_VERSION);
 
 module_param(esp_bus_reset_settle, int, 0);
 MODULE_PARM_DESC(esp_bus_reset_settle,
          "ESP scsi bus reset delay in seconds");
 
 module_param(esp_debug, int, 0);
 MODULE_PARM_DESC(esp_debug,
 "ESP bitmapped debugging message enable value:\n"
 "   0x00000001  Log interrupt events\n"
 "   0x00000002  Log scsi commands\n"
 "   0x00000004  Log resets\n"
 "   0x00000008  Log message in events\n"
 "   0x00000010  Log message out events\n"
 "   0x00000020  Log command completion\n"
 "   0x00000040  Log disconnects\n"
 "   0x00000080  Log data start\n"
 "   0x00000100  Log data done\n"
 "   0x00000200  Log reconnects\n"
 "   0x00000400  Log auto-sense data\n"
 );
 
 module_init(esp_init);
 module_exit(esp_exit);
 
 #ifdef CONFIG_SCSI_ESP_PIO
 static inline unsigned int esp_wait_for_fifo(struct esp *esp)
 {
     int i = 500000;
 
     do {
         unsigned int fbytes = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
 
         if (fbytes)
             return fbytes;
 
         udelay(1);
     } while (--i);
 
     shost_printk(KERN_ERR, esp->host, "FIFO is empty. sreg [%02x]\n",
              esp_read8(ESP_STATUS));
     return 0;
 }
 
 static inline int esp_wait_for_intr(struct esp *esp)
 {
     int i = 500000;
 
     do {
         esp->sreg = esp_read8(ESP_STATUS);
         if (esp->sreg & ESP_STAT_INTR)
             return 0;
 
         udelay(1);
     } while (--i);
 
     shost_printk(KERN_ERR, esp->host, "IRQ timeout. sreg [%02x]\n",
              esp->sreg);
     return 1;
 }
 
 #define ESP_FIFO_SIZE 16
 
 void esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count,
               u32 dma_count, int write, u8 cmd)
 {
     u8 phase = esp->sreg & ESP_STAT_PMASK;
 
     cmd &= ~ESP_CMD_DMA;
     esp->send_cmd_error = 0;
 
     if (write) {
         u8 *dst = (u8 *)addr;
         u8 mask = ~(phase == ESP_MIP ? ESP_INTR_FDONE : ESP_INTR_BSERV);
 
         scsi_esp_cmd(esp, cmd);
 
         while (1) {
             if (!esp_wait_for_fifo(esp))
                 break;
 
             *dst++ = readb(esp->fifo_reg);
             --esp_count;
 
             if (!esp_count)
                 break;
 
             if (esp_wait_for_intr(esp)) {
                 esp->send_cmd_error = 1;
                 break;
             }
 
             if ((esp->sreg & ESP_STAT_PMASK) != phase)
                 break;
 
             esp->ireg = esp_read8(ESP_INTRPT);
             if (esp->ireg & mask) {
                 esp->send_cmd_error = 1;
                 break;
             }
 
             if (phase == ESP_MIP)
                 esp_write8(ESP_CMD_MOK, ESP_CMD);
 
             esp_write8(ESP_CMD_TI, ESP_CMD);
         }
     } else {
         unsigned int n = ESP_FIFO_SIZE;
         u8 *src = (u8 *)addr;
 
         scsi_esp_cmd(esp, ESP_CMD_FLUSH);
 
         if (n > esp_count)
             n = esp_count;
         writesb(esp->fifo_reg, src, n);
         src += n;
         esp_count -= n;
 
         scsi_esp_cmd(esp, cmd);
 
         while (esp_count) {
             if (esp_wait_for_intr(esp)) {
                 esp->send_cmd_error = 1;
                 break;
             }
 
             if ((esp->sreg & ESP_STAT_PMASK) != phase)
                 break;
 
             esp->ireg = esp_read8(ESP_INTRPT);
             if (esp->ireg & ~ESP_INTR_BSERV) {
                 esp->send_cmd_error = 1;
                 break;
             }
 
             n = ESP_FIFO_SIZE -
                 (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES);
 
             if (n > esp_count)
                 n = esp_count;
             writesb(esp->fifo_reg, src, n);
             src += n;
             esp_count -= n;
 
             esp_write8(ESP_CMD_TI, ESP_CMD);
         }
     }
 
     esp->send_cmd_residual = esp_count;
 }
 EXPORT_SYMBOL(esp_send_pio_cmd);
 #endif