From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maciej Rutecki Subject: Re: [PATCH] thinkpad-acpi: fix potential suspend blocking issue Date: Tue, 5 Mar 2013 20:18:52 +0100 Message-ID: <201303052018.52320.maciej.rutecki@gmail.com> References: <201303042055.38040.maciej.rutecki@gmail.com> <1362504883-9180-1-git-send-email-msb@chromium.org> Reply-To: maciej.rutecki@gmail.com Mime-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ee0-f53.google.com ([74.125.83.53]:50518 "EHLO mail-ee0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752847Ab3CETS5 (ORCPT ); Tue, 5 Mar 2013 14:18:57 -0500 In-Reply-To: <1362504883-9180-1-git-send-email-msb@chromium.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Mandeep Singh Baines Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, ibm-acpi@hmh.eng.br, ibm-acpi-devel@lists.sourceforge.net, platform-driver-x86@vger.kernel.org, Aaron Lu , Henrique de Moraes Holschuh , Tejun Heo , Oleg Nesterov , Andrew Morton On wtorek, 5 marca 2013 o 18:34:43 Mandeep Singh Baines wrote: > Fixes the following lockdep error: > > [ BUG: ktpacpi_nvramd/446 still has locks held! ] > > hotkey_kthread() calls set_freezable() after acquiring the > hotkey_kthread_mutex(). set_freezable() calls try_to_freeze(). > This could block suspend if we were to freeze at this point > and another task were to block on the mutex, potentially via > writing to one of the sysfs attrs. This race is unlikely but > can be easily fixed by moving the set_freezable() call. > > Reported-by: Maciej Rutecki > Signed-off-by: Mandeep Singh Baines > CC: Aaron Lu > CC: Henrique de Moraes Holschuh > CC: Tejun Heo > CC: Oleg Nesterov > CC: Andrew Morton Tested-by: Maciej Rutecki Patch fixes the problem. Thanks! Regards -- Maciej Rutecki http://www.mrutecki.pl