leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

mmc: core: Prevent too long response times for suspend

Browse Source 
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>
This commit is contained in:
Ulf Hansson 2011-10-13 16:03:58 +02:00 committed by Chris Ball
parent b4625dab2c
commit b6ad726e3f
1 changed files with 27 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
drivers/mmc/core/core.c
View File

@ -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);