xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mmc: host: Add facility to support re-tuning

Browse Source 
Currently, there is core support for tuning during
initialization. There can also be a need to re-tune
periodically (e.g. sdhci) or to re-tune after the
host controller is powered off (e.g. after PM
runtime suspend / resume) or to re-tune in response
to CRC errors.

The main requirements for re-tuning are:
  - ability to enable / disable re-tuning
  - ability to flag that re-tuning is needed
  - ability to re-tune before any request
  - ability to hold off re-tuning if the card is busy
  - ability to hold off re-tuning if re-tuning is in
  progress
  - ability to run a re-tuning timer

To support those requirements 7 members are added to struct
mmc_host:

  unsigned int		can_retune:1;	/* re-tuning can be used */
  unsigned int		doing_retune:1;	/* re-tuning in progress */
  unsigned int		retune_now:1;   /* do re-tuning at next req */
  int			need_retune;	/* re-tuning is needed */
  int			hold_retune;	/* hold off re-tuning */
  unsigned int		retune_period;  /* re-tuning period in secs */
  struct timer_list	retune_timer;	/* for periodic re-tuning */

need_retune is an integer so it can be set without needing
synchronization. hold_retune is a integer to allow nesting.

Various simple functions are provided to set / clear those
variables.

Subsequent patches take those functions into use.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Adrian Hunter
2015-05-07 13:10:12 +03:00
committed by Ulf Hansson
parent 59d22309c4
commit dfa13ebbe3
3 changed files with 97 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
include/linux/mmc/host.h
View File

@@ -12,6 +12,7 @@
#include <linux/leds.h>
#include <linux/mutex.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/fault-inject.h>
@@ -321,10 +322,18 @@ struct mmc_host {
#ifdef CONFIG_MMC_DEBUG
unsigned int removed:1; /* host is being removed */
#endif
unsigned int can_retune:1; /* re-tuning can be used */
unsigned int doing_retune:1; /* re-tuning in progress */
unsigned int retune_now:1; /* do re-tuning at next req */
int rescan_disable; /* disable card detection */
int rescan_entered; /* used with nonremovable devices */
int need_retune; /* re-tuning is needed */
int hold_retune; /* hold off re-tuning */
unsigned int retune_period; /* re-tuning period in secs */
struct timer_list retune_timer; /* for periodic re-tuning */
bool trigger_card_event; /* card_event necessary */
struct mmc_card *card; /* device attached to this host */
@@ -513,4 +522,18 @@ static inline bool mmc_card_hs400(struct mmc_card *card)
return card->host->ios.timing == MMC_TIMING_MMC_HS400;
}
void mmc_retune_timer_stop(struct mmc_host *host);
static inline void mmc_retune_needed(struct mmc_host *host)
{
if (host->can_retune)
host->need_retune = 1;
}
static inline void mmc_retune_recheck(struct mmc_host *host)
{
if (host->hold_retune <= 1)
host->retune_now = 1;
}
#endif /* LINUX_MMC_HOST_H */