From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752585AbaBSBw4 (ORCPT ); Tue, 18 Feb 2014 20:52:56 -0500 Received: from mail-pb0-f52.google.com ([209.85.160.52]:33980 "EHLO mail-pb0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751448AbaBSBwW (ORCPT ); Tue, 18 Feb 2014 20:52:22 -0500 From: Sebastian Capella To: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linaro-kernel@lists.linaro.org, linux-arm-kernel@lists.infradead.org Cc: Sebastian Capella , Russ Dill , Ming Lei , Greg Kroah-Hartman Subject: [PATCH RFC v1 2/3] Fix hibernation restore hang in freeze_processes Date: Tue, 18 Feb 2014 17:52:08 -0800 Message-Id: <1392774729-3235-3-git-send-email-sebastian.capella@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1392774729-3235-1-git-send-email-sebastian.capella@linaro.org> References: <1392774729-3235-1-git-send-email-sebastian.capella@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Cc: Russ Dill Cc: Ming Lei Cc: Greg Kroah-Hartman --- drivers/base/firmware_class.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index eb8fb94..e2b51f8 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -1541,6 +1541,7 @@ 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; -- 1.7.9.5 From mboxrd@z Thu Jan 1 00:00:00 1970 From: sebastian.capella@linaro.org (Sebastian Capella) Date: Tue, 18 Feb 2014 17:52:08 -0800 Subject: [PATCH RFC v1 2/3] Fix hibernation restore hang in freeze_processes In-Reply-To: <1392774729-3235-1-git-send-email-sebastian.capella@linaro.org> References: <1392774729-3235-1-git-send-email-sebastian.capella@linaro.org> Message-ID: <1392774729-3235-3-git-send-email-sebastian.capella@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 Cc: Russ Dill Cc: Ming Lei Cc: Greg Kroah-Hartman --- drivers/base/firmware_class.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index eb8fb94..e2b51f8 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -1541,6 +1541,7 @@ 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; -- 1.7.9.5