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

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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: Ulf Hansson <ulf.hansson@stericsson.com>
Tested-by: Daniel Drake <dsd@laptop.org>
[stable@: please apply to 3.2-stable and 3.3-stable]
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Ulf Hansson 2012-04-19 11:55:25 +02:00 committed by Chris Ball
parent e1631f989e
commit 7c57091940
1 changed files with 20 additions and 35 deletions
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55
drivers/mmc/core/core.c
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@ -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;
}
@ -2272,49 +2274,32 @@ 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) {
err = host->bus_ops->suspend(host);
}
mmc_release_host(host);
if (host->bus_ops->suspend)
err = host->bus_ops->suspend(host);
if (err == -ENOSYS || !host->bus_ops->resume) {
/*
* We simply "remove" the card in this case.
* It will be redetected on resume. (Calling
* bus_ops->remove() with a claimed host can
* deadlock.)
*/
if (host->bus_ops->remove)
host->bus_ops->remove(host);
mmc_claim_host(host);
mmc_detach_bus(host);
mmc_power_off(host);
mmc_release_host(host);
host->pm_flags = 0;
err = 0;
}
} else {
err = -EBUSY;
if (err == -ENOSYS || !host->bus_ops->resume) {
/*
* We simply "remove" the card in this case.
* It will be redetected on resume. (Calling
* bus_ops->remove() with a claimed host can
* deadlock.)
*/
if (host->bus_ops->remove)
host->bus_ops->remove(host);
mmc_claim_host(host);
mmc_detach_bus(host);
mmc_power_off(host);
mmc_release_host(host);
host->pm_flags = 0;
err = 0;
}
}
mmc_bus_put(host);