mmc: core: Add MMC_CAP_RUNTIME_RESUME to resume at runtime_resume
In some environments it is to prefer to postpone the resume of the card
device until runtime_resume is being carried out, since it will mean a
signficant decrease of the total system resume time.
The reason of the decreased resume time is simply because of the actual
re-initalization of the card, which typically takes hundreds of
milliseconds, is performed outside the resume sequence and wont thus
affect it.
For removable card, the detect work tries to re-detect the card to make
sure it is still present, as a part of that sequence the card will also
be runtime_resumed and thus also fully resumed.
For a non-removable card, typically a mmc blk request will trigger a
runtime_resume and thus fully resume the card. This also means the
first request will likely suffer from an inital latency since the
re-initialization of the card needs to be performed.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 447fa8e..6f42050 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1139,11 +1139,13 @@
*/
static int mmc_sd_resume(struct mmc_host *host)
{
- int err;
+ int err = 0;
- err = _mmc_sd_resume(host);
- pm_runtime_set_active(&host->card->dev);
- pm_runtime_mark_last_busy(&host->card->dev);
+ if (!(host->caps & MMC_CAP_RUNTIME_RESUME)) {
+ err = _mmc_sd_resume(host);
+ pm_runtime_set_active(&host->card->dev);
+ pm_runtime_mark_last_busy(&host->card->dev);
+ }
pm_runtime_enable(&host->card->dev);
return err;
@@ -1174,7 +1176,7 @@
{
int err;
- if (!(host->caps & MMC_CAP_AGGRESSIVE_PM))
+ if (!(host->caps & (MMC_CAP_AGGRESSIVE_PM | MMC_CAP_RUNTIME_RESUME)))
return 0;
err = _mmc_sd_resume(host);