PM / hibernate: Fix restore hang in freeze_processes()

During restore, pm_notifier chain are called with
PM_RESTORE_PREPARE.  The firmware_class driver handler
fw_pm_notify does not have a handler for this.  As a result,
it keeps a reader on the kmod.c umhelper_sem.  During
freeze_processes, the call to __usermodehelper_disable tries to
take a write lock on this semaphore and hangs waiting.

Signed-off-by: Sebastian Capella <sebastian.capella@linaro.org>
Acked-by: Ming Lei <ming.lei@canonical.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Sebastian Capella 2014-02-18 17:52:08 -08:00 committed by Rafael J. Wysocki
parent cfbf8d4857
commit f8d5b9e9e5

View File

@ -1580,6 +1580,7 @@ static int fw_pm_notify(struct notifier_block *notify_block,
switch (mode) {
case PM_HIBERNATION_PREPARE:
case PM_SUSPEND_PREPARE:
case PM_RESTORE_PREPARE:
kill_requests_without_uevent();
device_cache_fw_images();
break;