Commit 7c570919 authored by Ulf Hansson's avatar Ulf Hansson Committed by Chris Ball
Browse files

mmc: core: Do not pre-claim host in suspend 



Since SDIO drivers may want to do some SDIO operations in their suspend
callback functions, we must not keep the host claimed when calling them.

Daniel Drake reported that libertas_sdio encountered a deadlock in its
suspend function.

Signed-off-by: default avatarUlf Hansson <ulf.hansson@stericsson.com>
Tested-by: default avatarDaniel Drake <dsd@laptop.org>
[stable@: please apply to 3.2-stable and 3.3-stable]
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent e1631f98

drivers/mmc/core/core.c

+20 −35
Original line number Diff line number Diff line
@@ -2238,6 +2238,7 @@ int mmc_cache_ctrl(struct mmc_host *host, u8 enable) 
			mmc_card_is_removable(host))

		return err;



	mmc_claim_host(host);

	if (card && mmc_card_mmc(card) &&

			(card->ext_csd.cache_size > 0)) {

		enable = !!enable;
@@ -2255,6 +2256,7 @@ int mmc_cache_ctrl(struct mmc_host *host, u8 enable) 
				card->ext_csd.cache_ctrl = enable;

		}

	}

	mmc_release_host(host);



	return err;

}
@@ -2272,30 +2274,16 @@ int mmc_suspend_host(struct mmc_host *host) 


	cancel_delayed_work(&host->detect);

	mmc_flush_scheduled_work();

	if (mmc_try_claim_host(host)) {

		err = mmc_cache_ctrl(host, 0);

		mmc_release_host(host);

	} else {

		err = -EBUSY;

	}



	err = mmc_cache_ctrl(host, 0);

	if (err)

		goto out;



	mmc_bus_get(host);

	if (host->bus_ops && !host->bus_dead) {



		/*

		 * A long response time is not acceptable for device drivers

		 * when doing suspend. Prevent mmc_claim_host in the suspend

		 * sequence, to potentially wait "forever" by trying to

		 * pre-claim the host.

		 */

		if (mmc_try_claim_host(host)) {

			if (host->bus_ops->suspend) {

		if (host->bus_ops->suspend)

			err = host->bus_ops->suspend(host);

			}

			mmc_release_host(host);



		if (err == -ENOSYS || !host->bus_ops->resume) {

			/*
@@ -2313,9 +2301,6 @@ int mmc_suspend_host(struct mmc_host *host) 
			host->pm_flags = 0;

			err = 0;

		}

		} else {

			err = -EBUSY;

		}

	}

	mmc_bus_put(host);

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