From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sebastian Capella , Ming Lei , "Rafael J. Wysocki" Subject: [PATCH 3.13 160/172] PM / hibernate: Fix restore hang in freeze_processes() Date: Tue, 4 Mar 2014 12:04:04 -0800 Message-Id: <20140304200304.835191837@linuxfoundation.org> In-Reply-To: <20140304200259.626667112@linuxfoundation.org> References: <20140304200259.626667112@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Capella 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 Acked-by: Ming Lei Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/base/firmware_class.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -1541,6 +1541,7 @@ static int fw_pm_notify(struct notifier_ switch (mode) { case PM_HIBERNATION_PREPARE: case PM_SUSPEND_PREPARE: + case PM_RESTORE_PREPARE: kill_requests_without_uevent(); device_cache_fw_images(); break;