PM / hibernate: Fix restore hang in freeze_processes()
authorSebastian Capella <sebastian.capella@linaro.org>
Wed, 19 Feb 2014 01:52:08 +0000 (17:52 -0800)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Wed, 26 Feb 2014 00:13:15 +0000 (01:13 +0100)
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>
drivers/base/firmware_class.c

index 8a97ddfa61222db79506dcecebc619ab5a333865..c30df50e4440c3af5639af58dd567c37e8bf40e6 100644 (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;