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authorUlf Hansson <ulf.hansson@stericsson.com>2011-10-13 16:03:58 +0200
committerChris Ball <cjb@laptop.org>2011-10-26 16:32:31 -0400
commitb6ad726e3fe69e1ff3c3b2ad272ba3e4c376cd6a (patch)
treedc2413bb2454ca3aec4c2a5c894c7b926690abcb /drivers/mmc
parentb4625dab2c618eb87e177761dda3182b4cfaa604 (diff)
downloadlinux-linaro-stable-b6ad726e3fe69e1ff3c3b2ad272ba3e4c376cd6a.tar.gz
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.c42
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);