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>
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