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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
 /*
  *  linux/drivers/mmc/core/sdio_io.c
  *
  *  Copyright 2007-2008 Pierre Ossman
  */
 
 #include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/mmc/host.h>
 #include <linux/mmc/card.h>
 #include <linux/mmc/sdio.h>
 #include <linux/mmc/sdio_func.h>
 
 #include "sdio_ops.h"
 #include "core.h"
 #include "card.h"
 #include "host.h"
 
 /**
  *  sdio_claim_host - exclusively claim a bus for a certain SDIO function
  *  @func: SDIO function that will be accessed
  *
  *  Claim a bus for a set of operations. The SDIO function given
  *  is used to figure out which bus is relevant.
  */
 void sdio_claim_host(struct sdio_func *func)
 {
     if (WARN_ON(!func))
         return;
 
     mmc_claim_host(func->card->host);
 }
 EXPORT_SYMBOL_GPL(sdio_claim_host);
 
 /**
  *  sdio_release_host - release a bus for a certain SDIO function
  *  @func: SDIO function that was accessed
  *
  *  Release a bus, allowing others to claim the bus for their
  *  operations.
  */
 void sdio_release_host(struct sdio_func *func)
 {
     if (WARN_ON(!func))
         return;
 
     mmc_release_host(func->card->host);
 }
 EXPORT_SYMBOL_GPL(sdio_release_host);
 
 /**
  *  sdio_enable_func - enables a SDIO function for usage
  *  @func: SDIO function to enable
  *
  *  Powers up and activates a SDIO function so that register
  *  access is possible.
  */
 int sdio_enable_func(struct sdio_func *func)
 {
     int ret;
     unsigned char reg;
     unsigned long timeout;
 
     if (!func)
         return -EINVAL;
 
     pr_debug("SDIO: Enabling device %s...\n", sdio_func_id(func));
 
     ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IOEx, 0, &reg);
     if (ret)
         goto err;
 
     reg |= 1 << func->num;
 
     ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IOEx, reg, NULL);
     if (ret)
         goto err;
 
     timeout = jiffies + msecs_to_jiffies(func->enable_timeout);
 
     while (1) {
         ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IORx, 0, &reg);
         if (ret)
             goto err;
         if (reg & (1 << func->num))
             break;
         ret = -ETIME;
         if (time_after(jiffies, timeout))
             goto err;
     }
 
     pr_debug("SDIO: Enabled device %s\n", sdio_func_id(func));
 
     return 0;
 
 err:
     pr_debug("SDIO: Failed to enable device %s\n", sdio_func_id(func));
     return ret;
 }
 EXPORT_SYMBOL_GPL(sdio_enable_func);
 
 /**
  *  sdio_disable_func - disable a SDIO function
  *  @func: SDIO function to disable
  *
  *  Powers down and deactivates a SDIO function. Register access
  *  to this function will fail until the function is reenabled.
  */
 int sdio_disable_func(struct sdio_func *func)
 {
     int ret;
     unsigned char reg;
 
     if (!func)
         return -EINVAL;
 
     pr_debug("SDIO: Disabling device %s...\n", sdio_func_id(func));
 
     ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IOEx, 0, &reg);
     if (ret)
         goto err;
 
     reg &= ~(1 << func->num);
 
     ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IOEx, reg, NULL);
     if (ret)
         goto err;
 
     pr_debug("SDIO: Disabled device %s\n", sdio_func_id(func));
 
     return 0;
 
 err:
     pr_debug("SDIO: Failed to disable device %s\n", sdio_func_id(func));
     return ret;
 }
 EXPORT_SYMBOL_GPL(sdio_disable_func);
 
 /**
  *  sdio_set_block_size - set the block size of an SDIO function
  *  @func: SDIO function to change
  *  @blksz: new block size or 0 to use the default.
  *
  *  The default block size is the largest supported by both the function
  *  and the host, with a maximum of 512 to ensure that arbitrarily sized
  *  data transfer use the optimal (least) number of commands.
  *
  *  A driver may call this to override the default block size set by the
  *  core. This can be used to set a block size greater than the maximum
  *  that reported by the card; it is the driver's responsibility to ensure
  *  it uses a value that the card supports.
  *
  *  Returns 0 on success, -EINVAL if the host does not support the
  *  requested block size, or -EIO (etc.) if one of the resultant FBR block
  *  size register writes failed.
  *
  */
 int sdio_set_block_size(struct sdio_func *func, unsigned blksz)
 {
     int ret;
 
     if (blksz > func->card->host->max_blk_size)
         return -EINVAL;
 
     if (blksz == 0) {
         blksz = min(func->max_blksize, func->card->host->max_blk_size);
         blksz = min(blksz, 512u);
     }
 
     ret = mmc_io_rw_direct(func->card, 1, 0,
         SDIO_FBR_BASE(func->num) + SDIO_FBR_BLKSIZE,
         blksz & 0xff, NULL);
     if (ret)
         return ret;
     ret = mmc_io_rw_direct(func->card, 1, 0,
         SDIO_FBR_BASE(func->num) + SDIO_FBR_BLKSIZE + 1,
         (blksz >> 8) & 0xff, NULL);
     if (ret)
         return ret;
     func->cur_blksize = blksz;
     return 0;
 }
 EXPORT_SYMBOL_GPL(sdio_set_block_size);
 
 /*
  * Calculate the maximum byte mode transfer size
  */
 static inline unsigned int sdio_max_byte_size(struct sdio_func *func)
 {
     unsigned mval = func->card->host->max_blk_size;
 
     if (mmc_blksz_for_byte_mode(func->card))
         mval = min(mval, func->cur_blksize);
     else
         mval = min(mval, func->max_blksize);
 
     if (mmc_card_broken_byte_mode_512(func->card))
         return min(mval, 511u);
 
     return min(mval, 512u); /* maximum size for byte mode */
 }
 
 /*
  * This is legacy code, which needs to be re-worked some day. Basically we need
  * to take into account the properties of the host, as to enable the SDIO func
  * driver layer to allocate optimal buffers.
  */
 static inline unsigned int _sdio_align_size(unsigned int sz)
 {
     /*
      * FIXME: We don't have a system for the controller to tell
      * the core about its problems yet, so for now we just 32-bit
      * align the size.
      */
     return ALIGN(sz, 4);
 }
 
 /**
  *  sdio_align_size - pads a transfer size to a more optimal value
  *  @func: SDIO function
  *  @sz: original transfer size
  *
  *  Pads the original data size with a number of extra bytes in
  *  order to avoid controller bugs and/or performance hits
  *  (e.g. some controllers revert to PIO for certain sizes).
  *
  *  If possible, it will also adjust the size so that it can be
  *  handled in just a single request.
  *
  *  Returns the improved size, which might be unmodified.
  */
 unsigned int sdio_align_size(struct sdio_func *func, unsigned int sz)
 {
     unsigned int orig_sz;
     unsigned int blk_sz, byte_sz;
     unsigned chunk_sz;
 
     orig_sz = sz;
 
     /*
      * Do a first check with the controller, in case it
      * wants to increase the size up to a point where it
      * might need more than one block.
      */
     sz = _sdio_align_size(sz);
 
     /*
      * If we can still do this with just a byte transfer, then
      * we're done.
      */
     if (sz <= sdio_max_byte_size(func))
         return sz;
 
     if (func->card->cccr.multi_block) {
         /*
          * Check if the transfer is already block aligned
          */
         if ((sz % func->cur_blksize) == 0)
             return sz;
 
         /*
          * Realign it so that it can be done with one request,
          * and recheck if the controller still likes it.
          */
         blk_sz = ((sz + func->cur_blksize - 1) /
             func->cur_blksize) * func->cur_blksize;
         blk_sz = _sdio_align_size(blk_sz);
 
         /*
          * This value is only good if it is still just
          * one request.
          */
         if ((blk_sz % func->cur_blksize) == 0)
             return blk_sz;
 
         /*
          * We failed to do one request, but at least try to
          * pad the remainder properly.
          */
         byte_sz = _sdio_align_size(sz % func->cur_blksize);
         if (byte_sz <= sdio_max_byte_size(func)) {
             blk_sz = sz / func->cur_blksize;
             return blk_sz * func->cur_blksize + byte_sz;
         }
     } else {
         /*
          * We need multiple requests, so first check that the
          * controller can handle the chunk size;
          */
         chunk_sz = _sdio_align_size(sdio_max_byte_size(func));
         if (chunk_sz == sdio_max_byte_size(func)) {
             /*
              * Fix up the size of the remainder (if any)
              */
             byte_sz = orig_sz % chunk_sz;
             if (byte_sz) {
                 byte_sz = _sdio_align_size(byte_sz);
             }
 
             return (orig_sz / chunk_sz) * chunk_sz + byte_sz;
         }
     }
 
     /*
      * The controller is simply incapable of transferring the size
      * we want in decent manner, so just return the original size.
      */
     return orig_sz;
 }
 EXPORT_SYMBOL_GPL(sdio_align_size);
 
 /* Split an arbitrarily sized data transfer into several
  * IO_RW_EXTENDED commands. */
 static int sdio_io_rw_ext_helper(struct sdio_func *func, int write,
     unsigned addr, int incr_addr, u8 *buf, unsigned size)
 {
     unsigned remainder = size;
     unsigned max_blocks;
     int ret;
 
     if (!func || (func->num > 7))
         return -EINVAL;
 
     /* Do the bulk of the transfer using block mode (if supported). */
     if (func->card->cccr.multi_block && (size > sdio_max_byte_size(func))) {
         /* Blocks per command is limited by host count, host transfer
          * size and the maximum for IO_RW_EXTENDED of 511 blocks. */
         max_blocks = min(func->card->host->max_blk_count, 511u);
 
         while (remainder >= func->cur_blksize) {
             unsigned blocks;
 
             blocks = remainder / func->cur_blksize;
             if (blocks > max_blocks)
                 blocks = max_blocks;
             size = blocks * func->cur_blksize;
 
             ret = mmc_io_rw_extended(func->card, write,
                 func->num, addr, incr_addr, buf,
                 blocks, func->cur_blksize);
             if (ret)
                 return ret;
 
             remainder -= size;
             buf += size;
             if (incr_addr)
                 addr += size;
         }
     }
 
     /* Write the remainder using byte mode. */
     while (remainder > 0) {
         size = min(remainder, sdio_max_byte_size(func));
 
         /* Indicate byte mode by setting "blocks" = 0 */
         ret = mmc_io_rw_extended(func->card, write, func->num, addr,
              incr_addr, buf, 0, size);
         if (ret)
             return ret;
 
         remainder -= size;
         buf += size;
         if (incr_addr)
             addr += size;
     }
     return 0;
 }
 
 /**
  *  sdio_readb - read a single byte from a SDIO function
  *  @func: SDIO function to access
  *  @addr: address to read
  *  @err_ret: optional status value from transfer
  *
  *  Reads a single byte from the address space of a given SDIO
  *  function. If there is a problem reading the address, 0xff
  *  is returned and @err_ret will contain the error code.
  */
 u8 sdio_readb(struct sdio_func *func, unsigned int addr, int *err_ret)
 {
     int ret;
     u8 val;
 
     if (!func) {
         if (err_ret)
             *err_ret = -EINVAL;
         return 0xFF;
     }
 
     ret = mmc_io_rw_direct(func->card, 0, func->num, addr, 0, &val);
     if (err_ret)
         *err_ret = ret;
     if (ret)
         return 0xFF;
 
     return val;
 }
 EXPORT_SYMBOL_GPL(sdio_readb);
 
 /**
  *  sdio_writeb - write a single byte to a SDIO function
  *  @func: SDIO function to access
  *  @b: byte to write
  *  @addr: address to write to
  *  @err_ret: optional status value from transfer
  *
  *  Writes a single byte to the address space of a given SDIO
  *  function. @err_ret will contain the status of the actual
  *  transfer.
  */
 void sdio_writeb(struct sdio_func *func, u8 b, unsigned int addr, int *err_ret)
 {
     int ret;
 
     if (!func) {
         if (err_ret)
             *err_ret = -EINVAL;
         return;
     }
 
     ret = mmc_io_rw_direct(func->card, 1, func->num, addr, b, NULL);
     if (err_ret)
         *err_ret = ret;
 }
 EXPORT_SYMBOL_GPL(sdio_writeb);
 
 /**
  *  sdio_writeb_readb - write and read a byte from SDIO function
  *  @func: SDIO function to access
  *  @write_byte: byte to write
  *  @addr: address to write to
  *  @err_ret: optional status value from transfer
  *
  *  Performs a RAW (Read after Write) operation as defined by SDIO spec -
  *  single byte is written to address space of a given SDIO function and
  *  response is read back from the same address, both using single request.
  *  If there is a problem with the operation, 0xff is returned and
  *  @err_ret will contain the error code.
  */
 u8 sdio_writeb_readb(struct sdio_func *func, u8 write_byte,
     unsigned int addr, int *err_ret)
 {
     int ret;
     u8 val;
 
     ret = mmc_io_rw_direct(func->card, 1, func->num, addr,
             write_byte, &val);
     if (err_ret)
         *err_ret = ret;
     if (ret)
         return 0xff;
 
     return val;
 }
 EXPORT_SYMBOL_GPL(sdio_writeb_readb);
 
 /**
  *  sdio_memcpy_fromio - read a chunk of memory from a SDIO function
  *  @func: SDIO function to access
  *  @dst: buffer to store the data
  *  @addr: address to begin reading from
  *  @count: number of bytes to read
  *
  *  Reads from the address space of a given SDIO function. Return
  *  value indicates if the transfer succeeded or not.
  */
 int sdio_memcpy_fromio(struct sdio_func *func, void *dst,
     unsigned int addr, int count)
 {
     return sdio_io_rw_ext_helper(func, 0, addr, 1, dst, count);
 }
 EXPORT_SYMBOL_GPL(sdio_memcpy_fromio);
 
 /**
  *  sdio_memcpy_toio - write a chunk of memory to a SDIO function
  *  @func: SDIO function to access
  *  @addr: address to start writing to
  *  @src: buffer that contains the data to write
  *  @count: number of bytes to write
  *
  *  Writes to the address space of a given SDIO function. Return
  *  value indicates if the transfer succeeded or not.
  */
 int sdio_memcpy_toio(struct sdio_func *func, unsigned int addr,
     void *src, int count)
 {
     return sdio_io_rw_ext_helper(func, 1, addr, 1, src, count);
 }
 EXPORT_SYMBOL_GPL(sdio_memcpy_toio);
 
 /**
  *  sdio_readsb - read from a FIFO on a SDIO function
  *  @func: SDIO function to access
  *  @dst: buffer to store the data
  *  @addr: address of (single byte) FIFO
  *  @count: number of bytes to read
  *
  *  Reads from the specified FIFO of a given SDIO function. Return
  *  value indicates if the transfer succeeded or not.
  */
 int sdio_readsb(struct sdio_func *func, void *dst, unsigned int addr,
     int count)
 {
     return sdio_io_rw_ext_helper(func, 0, addr, 0, dst, count);
 }
 EXPORT_SYMBOL_GPL(sdio_readsb);
 
 /**
  *  sdio_writesb - write to a FIFO of a SDIO function
  *  @func: SDIO function to access
  *  @addr: address of (single byte) FIFO
  *  @src: buffer that contains the data to write
  *  @count: number of bytes to write
  *
  *  Writes to the specified FIFO of a given SDIO function. Return
  *  value indicates if the transfer succeeded or not.
  */
 int sdio_writesb(struct sdio_func *func, unsigned int addr, void *src,
     int count)
 {
     return sdio_io_rw_ext_helper(func, 1, addr, 0, src, count);
 }
 EXPORT_SYMBOL_GPL(sdio_writesb);
 
 /**
  *  sdio_readw - read a 16 bit integer from a SDIO function
  *  @func: SDIO function to access
  *  @addr: address to read
  *  @err_ret: optional status value from transfer
  *
  *  Reads a 16 bit integer from the address space of a given SDIO
  *  function. If there is a problem reading the address, 0xffff
  *  is returned and @err_ret will contain the error code.
  */
 u16 sdio_readw(struct sdio_func *func, unsigned int addr, int *err_ret)
 {
     int ret;
 
     ret = sdio_memcpy_fromio(func, func->tmpbuf, addr, 2);
     if (err_ret)
         *err_ret = ret;
     if (ret)
         return 0xFFFF;
 
     return le16_to_cpup((__le16 *)func->tmpbuf);
 }
 EXPORT_SYMBOL_GPL(sdio_readw);
 
 /**
  *  sdio_writew - write a 16 bit integer to a SDIO function
  *  @func: SDIO function to access
  *  @b: integer to write
  *  @addr: address to write to
  *  @err_ret: optional status value from transfer
  *
  *  Writes a 16 bit integer to the address space of a given SDIO
  *  function. @err_ret will contain the status of the actual
  *  transfer.
  */
 void sdio_writew(struct sdio_func *func, u16 b, unsigned int addr, int *err_ret)
 {
     int ret;
 
     *(__le16 *)func->tmpbuf = cpu_to_le16(b);
 
     ret = sdio_memcpy_toio(func, addr, func->tmpbuf, 2);
     if (err_ret)
         *err_ret = ret;
 }
 EXPORT_SYMBOL_GPL(sdio_writew);
 
 /**
  *  sdio_readl - read a 32 bit integer from a SDIO function
  *  @func: SDIO function to access
  *  @addr: address to read
  *  @err_ret: optional status value from transfer
  *
  *  Reads a 32 bit integer from the address space of a given SDIO
  *  function. If there is a problem reading the address,
  *  0xffffffff is returned and @err_ret will contain the error
  *  code.
  */
 u32 sdio_readl(struct sdio_func *func, unsigned int addr, int *err_ret)
 {
     int ret;
 
     ret = sdio_memcpy_fromio(func, func->tmpbuf, addr, 4);
     if (err_ret)
         *err_ret = ret;
     if (ret)
         return 0xFFFFFFFF;
 
     return le32_to_cpup((__le32 *)func->tmpbuf);
 }
 EXPORT_SYMBOL_GPL(sdio_readl);
 
 /**
  *  sdio_writel - write a 32 bit integer to a SDIO function
  *  @func: SDIO function to access
  *  @b: integer to write
  *  @addr: address to write to
  *  @err_ret: optional status value from transfer
  *
  *  Writes a 32 bit integer to the address space of a given SDIO
  *  function. @err_ret will contain the status of the actual
  *  transfer.
  */
 void sdio_writel(struct sdio_func *func, u32 b, unsigned int addr, int *err_ret)
 {
     int ret;
 
     *(__le32 *)func->tmpbuf = cpu_to_le32(b);
 
     ret = sdio_memcpy_toio(func, addr, func->tmpbuf, 4);
     if (err_ret)
         *err_ret = ret;
 }
 EXPORT_SYMBOL_GPL(sdio_writel);
 
 /**
  *  sdio_f0_readb - read a single byte from SDIO function 0
  *  @func: an SDIO function of the card
  *  @addr: address to read
  *  @err_ret: optional status value from transfer
  *
  *  Reads a single byte from the address space of SDIO function 0.
  *  If there is a problem reading the address, 0xff is returned
  *  and @err_ret will contain the error code.
  */
 unsigned char sdio_f0_readb(struct sdio_func *func, unsigned int addr,
     int *err_ret)
 {
     int ret;
     unsigned char val;
 
     if (!func) {
         if (err_ret)
             *err_ret = -EINVAL;
         return 0xFF;
     }
 
     ret = mmc_io_rw_direct(func->card, 0, 0, addr, 0, &val);
     if (err_ret)
         *err_ret = ret;
     if (ret)
         return 0xFF;
 
     return val;
 }
 EXPORT_SYMBOL_GPL(sdio_f0_readb);
 
 /**
  *  sdio_f0_writeb - write a single byte to SDIO function 0
  *  @func: an SDIO function of the card
  *  @b: byte to write
  *  @addr: address to write to
  *  @err_ret: optional status value from transfer
  *
  *  Writes a single byte to the address space of SDIO function 0.
  *  @err_ret will contain the status of the actual transfer.
  *
  *  Only writes to the vendor specific CCCR registers (0xF0 -
  *  0xFF) are permiited; @err_ret will be set to -EINVAL for *
  *  writes outside this range.
  */
 void sdio_f0_writeb(struct sdio_func *func, unsigned char b, unsigned int addr,
     int *err_ret)
 {
     int ret;
 
     if (!func) {
         if (err_ret)
             *err_ret = -EINVAL;
         return;
     }
 
     if ((addr < 0xF0 || addr > 0xFF) && (!mmc_card_lenient_fn0(func->card))) {
         if (err_ret)
             *err_ret = -EINVAL;
         return;
     }
 
     ret = mmc_io_rw_direct(func->card, 1, 0, addr, b, NULL);
     if (err_ret)
         *err_ret = ret;
 }
 EXPORT_SYMBOL_GPL(sdio_f0_writeb);
 
 /**
  *  sdio_get_host_pm_caps - get host power management capabilities
  *  @func: SDIO function attached to host
  *
  *  Returns a capability bitmask corresponding to power management
  *  features supported by the host controller that the card function
  *  might rely upon during a system suspend.  The host doesn't need
  *  to be claimed, nor the function active, for this information to be
  *  obtained.
  */
 mmc_pm_flag_t sdio_get_host_pm_caps(struct sdio_func *func)
 {
     if (!func)
         return 0;
 
     return func->card->host->pm_caps;
 }
 EXPORT_SYMBOL_GPL(sdio_get_host_pm_caps);
 
 /**
  *  sdio_set_host_pm_flags - set wanted host power management capabilities
  *  @func: SDIO function attached to host
  *  @flags: Power Management flags to set
  *
  *  Set a capability bitmask corresponding to wanted host controller
  *  power management features for the upcoming suspend state.
  *  This must be called, if needed, each time the suspend method of
  *  the function driver is called, and must contain only bits that
  *  were returned by sdio_get_host_pm_caps().
  *  The host doesn't need to be claimed, nor the function active,
  *  for this information to be set.
  */
 int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags)
 {
     struct mmc_host *host;
 
     if (!func)
         return -EINVAL;
 
     host = func->card->host;
 
     if (flags & ~host->pm_caps)
         return -EINVAL;
 
     /* function suspend methods are serialized, hence no lock needed */
     host->pm_flags |= flags;
     return 0;
 }
 EXPORT_SYMBOL_GPL(sdio_set_host_pm_flags);
 
 /**
  *  sdio_retune_crc_disable - temporarily disable retuning on CRC errors
  *  @func: SDIO function attached to host
  *
  *  If the SDIO card is known to be in a state where it might produce
  *  CRC errors on the bus in response to commands (like if we know it is
  *  transitioning between power states), an SDIO function driver can
  *  call this function to temporarily disable the SD/MMC core behavior of
  *  triggering an automatic retuning.
  *
  *  This function should be called while the host is claimed and the host
  *  should remain claimed until sdio_retune_crc_enable() is called.
  *  Specifically, the expected sequence of calls is:
  *  - sdio_claim_host()
  *  - sdio_retune_crc_disable()
  *  - some number of calls like sdio_writeb() and sdio_readb()
  *  - sdio_retune_crc_enable()
  *  - sdio_release_host()
  */
 void sdio_retune_crc_disable(struct sdio_func *func)
 {
     func->card->host->retune_crc_disable = true;
 }
 EXPORT_SYMBOL_GPL(sdio_retune_crc_disable);
 
 /**
  *  sdio_retune_crc_enable - re-enable retuning on CRC errors
  *  @func: SDIO function attached to host
  *
  *  This is the compement to sdio_retune_crc_disable().
  */
 void sdio_retune_crc_enable(struct sdio_func *func)
 {
     func->card->host->retune_crc_disable = false;
 }
 EXPORT_SYMBOL_GPL(sdio_retune_crc_enable);
 
 /**
  *  sdio_retune_hold_now - start deferring retuning requests till release
  *  @func: SDIO function attached to host
  *
  *  This function can be called if it's currently a bad time to do
  *  a retune of the SDIO card.  Retune requests made during this time
  *  will be held and we'll actually do the retune sometime after the
  *  release.
  *
  *  This function could be useful if an SDIO card is in a power state
  *  where it can respond to a small subset of commands that doesn't
  *  include the retuning command.  Care should be taken when using
  *  this function since (presumably) the retuning request we might be
  *  deferring was made for a good reason.
  *
  *  This function should be called while the host is claimed.
  */
 void sdio_retune_hold_now(struct sdio_func *func)
 {
     mmc_retune_hold_now(func->card->host);
 }
 EXPORT_SYMBOL_GPL(sdio_retune_hold_now);
 
 /**
  *  sdio_retune_release - signal that it's OK to retune now
  *  @func: SDIO function attached to host
  *
  *  This is the complement to sdio_retune_hold_now().  Calling this
  *  function won't make a retune happen right away but will allow
  *  them to be scheduled normally.
  *
  *  This function should be called while the host is claimed.
  */
 void sdio_retune_release(struct sdio_func *func)
 {
     mmc_retune_release(func->card->host);
 }
 EXPORT_SYMBOL_GPL(sdio_retune_release);

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