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Commit ed919b01 authored by Ohad Ben-Cohen's avatar Ohad Ben-Cohen Committed by Chris Ball
Browse files

mmc: sdio: fix runtime PM anomalies by introducing MMC_CAP_POWER_OFF_CARD 



Some board/card/host configurations are not capable of powering off the
card after boot.

To support such configurations, and to allow smoother transition to
runtime PM behavior, MMC_CAP_POWER_OFF_CARD is added, so hosts need to
explicitly indicate whether it's OK to power off their cards after boot.

SDIO core will enable runtime PM for a card only if that cap is set.
As a result, the card will be powered down after boot, and will only
be powered up again when a driver is loaded (and then it's up to the
driver to decide whether power will be kept or not).

This will prevent sdio_bus_probe() failures with setups that do not
support powering off the card.

Reported-and-tested-by: default avatarDaniel Drake <dsd@laptop.org>
Reported-and-tested-by: default avatarArnd Hannemann <arnd@arndnet.de>
Signed-off-by: default avatarOhad Ben-Cohen <ohad@wizery.com>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 4d0812c3

drivers/mmc/core/sdio.c

+23 −14
Original line number Diff line number Diff line
@@ -547,9 +547,11 @@ static void mmc_sdio_detect(struct mmc_host *host) 
	BUG_ON(!host->card);



	/* Make sure card is powered before detecting it */

	if (host->caps & MMC_CAP_POWER_OFF_CARD) {

		err = pm_runtime_get_sync(&host->card->dev);

		if (err < 0)

			goto out;

	}



	mmc_claim_host(host);
@@ -571,6 +573,7 @@ static void mmc_sdio_detect(struct mmc_host *host) 
	 * is about to show up at this point, the _sync variant is

	 * desirable anyway.

	 */

	if (host->caps & MMC_CAP_POWER_OFF_CARD)

		pm_runtime_put_sync(&host->card->dev);



out:
@@ -727,6 +730,10 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr) 
		goto err;

	card = host->card;



	/*

	 * Enable runtime PM only if supported by host+card+board

	 */

	if (host->caps & MMC_CAP_POWER_OFF_CARD) {

		/*

		 * Let runtime PM core know our card is active

		 */
@@ -738,6 +745,7 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr) 
		 * Enable runtime PM for this card

		 */

		pm_runtime_enable(&card->dev);

	}



	/*

	 * The number of functions on the card is encoded inside
@@ -755,8 +763,9 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr) 
			goto remove;



		/*

		 * Enable Runtime PM for this func

		 * Enable Runtime PM for this func (if supported)

		 */

		if (host->caps & MMC_CAP_POWER_OFF_CARD)

			pm_runtime_enable(&card->sdio_func[i]->dev);

	}

drivers/mmc/core/sdio_bus.c

+22 −11
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <linux/pm_runtime.h>



#include <linux/mmc/card.h>

#include <linux/mmc/host.h>

#include <linux/mmc/sdio_func.h>



#include "sdio_cis.h"
@@ -132,9 +133,11 @@ static int sdio_bus_probe(struct device *dev) 
	 * it should call pm_runtime_put_noidle() in its probe routine and

	 * pm_runtime_get_noresume() in its remove routine.

	 */

	if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD) {

		ret = pm_runtime_get_sync(dev);

		if (ret < 0)

			goto out;

	}



	/* Set the default block size so the driver is sure it's something

	 * sensible. */
@@ -151,6 +154,7 @@ static int sdio_bus_probe(struct device *dev) 
	return 0;



disable_runtimepm:

	if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD)

		pm_runtime_put_noidle(dev);

out:

	return ret;
@@ -160,12 +164,14 @@ static int sdio_bus_remove(struct device *dev) 
{

	struct sdio_driver *drv = to_sdio_driver(dev->driver);

	struct sdio_func *func = dev_to_sdio_func(dev);

	int ret;

	int ret = 0;



	/* Make sure card is powered before invoking ->remove() */

	if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD) {

		ret = pm_runtime_get_sync(dev);

		if (ret < 0)

			goto out;

	}



	drv->remove(func);
@@ -178,9 +184,11 @@ static int sdio_bus_remove(struct device *dev) 
	}



	/* First, undo the increment made directly above */

	if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD)

		pm_runtime_put_noidle(dev);



	/* Then undo the runtime PM settings in sdio_bus_probe() */

	if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD)

		pm_runtime_put_noidle(dev);



out:
@@ -191,6 +199,8 @@ out: 


static int sdio_bus_pm_prepare(struct device *dev)

{

	struct sdio_func *func = dev_to_sdio_func(dev);



	/*

	 * Resume an SDIO device which was suspended at run time at this

	 * point, in order to allow standard SDIO suspend/resume paths
@@ -212,6 +222,7 @@ static int sdio_bus_pm_prepare(struct device *dev) 
	 * since there is little point in failing system suspend if a

	 * device can't be resumed.

	 */

	if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD)

		pm_runtime_resume(dev);



	return 0;

include/linux/mmc/host.h

+1 −0
Original line number Diff line number Diff line
@@ -168,6 +168,7 @@ struct mmc_host { 
						/* DDR mode at 1.8V */

#define MMC_CAP_1_2V_DDR	(1 << 12)	/* can support */

						/* DDR mode at 1.2V */

#define MMC_CAP_POWER_OFF_CARD	(1 << 13)	/* Can power off after boot */



	mmc_pm_flag_t		pm_caps;	/* supported pm features */