[1/4] mmc: core: Introduce MMC_CAP_SYNC_RUNTIME_PM

Message ID 20180531094041.27902-2-ulf.hansson@linaro.org
State New
Headers show
Series
  • mmc: rtsx_usb_sdmmc: Don't waste energy polling for cards
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Commit Message

Ulf Hansson May 31, 2018, 9:40 a.m.
To allow mmc host drivers to inform the mmc core about rather using
pm_runtime_put_sync_suspend() instead of pm_runtime_put_autosuspend(),
let's introduce MMC_CAP_SYNC_RUNTIME_PM.

This is especially useful for those mmc host drivers that don't benefit
from using the runtime PM autosuspend feature. Typically this is those that
relies on parent devices to power the card via runtime PM, like some USB
host drivers for example.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

---
 drivers/mmc/core/core.c  | 5 ++++-
 include/linux/mmc/host.h | 2 +-
 2 files changed, 5 insertions(+), 2 deletions(-)

-- 
2.17.0

Patch

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 281826d1fcca..fd366b3677b6 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -887,7 +887,10 @@  void mmc_release_host(struct mmc_host *host)
 		spin_unlock_irqrestore(&host->lock, flags);
 		wake_up(&host->wq);
 		pm_runtime_mark_last_busy(mmc_dev(host));
-		pm_runtime_put_autosuspend(mmc_dev(host));
+		if (host->caps & MMC_CAP_SYNC_RUNTIME_PM)
+			pm_runtime_put_sync_suspend(mmc_dev(host));
+		else
+			pm_runtime_put_autosuspend(mmc_dev(host));
 	}
 }
 EXPORT_SYMBOL(mmc_release_host);
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 64300a48dcce..f029675b9a52 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -324,7 +324,7 @@  struct mmc_host {
 #define MMC_CAP_UHS		(MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 | \
 				 MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | \
 				 MMC_CAP_UHS_DDR50)
-/* (1 << 21) is free for reuse */
+#define MMC_CAP_SYNC_RUNTIME_PM	(1 << 21)	/* Synced runtime PM suspends. */
 #define MMC_CAP_DRIVER_TYPE_A	(1 << 23)	/* Host supports Driver Type A */
 #define MMC_CAP_DRIVER_TYPE_C	(1 << 24)	/* Host supports Driver Type C */
 #define MMC_CAP_DRIVER_TYPE_D	(1 << 25)	/* Host supports Driver Type D */