[02/12,SRU,B,C,D,OEM-B] mmc: core: Introduce MMC_CAP_SYNC_RUNTIME_PM

Message ID 20190111083019.32135-3-acelan.kao@canonical.com
State New
Headers show
Series
  • To reduce the Realtek USB cardreader power consumption
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Commit Message

AceLan Kao Jan. 11, 2019, 8:30 a.m.
From: Ulf Hansson <ulf.hansson@linaro.org>

BugLink: https://bugs.launchpad.net/bugs/1811337

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>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
(cherry picked from commit 7d5ef512575663695cf85f3aeb985a0aeb03e364)
Signed-off-by: AceLan Kao <acelan.kao@canonical.com>
---
 drivers/mmc/core/core.c  | 5 ++++-
 include/linux/mmc/host.h | 2 +-
 2 files changed, 5 insertions(+), 2 deletions(-)

Patch

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index af194640dbc6..c36299d71e79 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1088,7 +1088,10 @@  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 b36723e8e99b..07aa01f5d8bd 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -323,7 +323,7 @@  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 */