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| author | Ulf Hansson <ulf.hansson@stericsson.com> | 2011-10-13 16:03:58 +0200 |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2011-10-26 16:32:31 -0400 |
| commit | b6ad726e3fe69e1ff3c3b2ad272ba3e4c376cd6a (patch) | |
| tree | dc2413bb2454ca3aec4c2a5c894c7b926690abcb /drivers/mmc | |
| parent | b4625dab2c618eb87e177761dda3182b4cfaa604 (diff) | |
| download | linux-b6ad726e3fe69e1ff3c3b2ad272ba3e4c376cd6a.tar.gz linux-b6ad726e3fe69e1ff3c3b2ad272ba3e4c376cd6a.tar.bz2 linux-b6ad726e3fe69e1ff3c3b2ad272ba3e4c376cd6a.zip | |
mmc: core: Prevent too long response times for suspend
While trying to suspend the mmc host there could still be
ongoing requests that we need to wait for. At the same time
a device driver must respond to a suspend request rather quickly.
Instead of potentially wait "forever" by claiming the host we now
"try" to claim the host instead. If it fails, -EBUSY is returned.
Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Reviewed-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/core/core.c | 42 |
1 files changed, 27 insertions, 15 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index fe65bb377e25..5278ffb20e74 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -2294,21 +2294,33 @@ int mmc_suspend_host(struct mmc_host *host) mmc_bus_get(host); if (host->bus_ops && !host->bus_dead) { - 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. - */ - 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; + + /* + * 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); + if (err == -ENOSYS || !host->bus_ops->resume) { + /* + * We simply "remove" the card in this case. + * It will be redetected on resume. + */ + 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_do_release_host(host); + } else { + err = -EBUSY; } } mmc_bus_put(host); |