From: Sebastian Capella <sebastian.capella@linaro.org>
Date: Wed, 19 Feb 2014 01:52:08 +0000 (-0800)
Subject: PM / hibernate: Fix restore hang in freeze_processes()
X-Git-Tag: submit/tizen_common/20140905.094502~501
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3787169fa3185aa8587972b5fdccbf700f60a4f1;p=sdk%2Femulator%2Femulator-kernel.git

PM / hibernate: Fix restore hang in freeze_processes()

commit f8d5b9e9e5372f0deb7bc1ab1088a9b60b0a793d upstream.

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>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 10a4467c63f1..701212ba38b7 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -1529,6 +1529,7 @@ 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;