From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from canardo.mork.no ([148.122.252.1]:52377 "EHLO canardo.mork.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751095AbbCILGr convert rfc822-to-8bit (ORCPT ); Mon, 9 Mar 2015 07:06:47 -0400 From: =?utf-8?Q?Bj=C3=B8rn_Mork?= To: Laurent Pinchart Cc: linux-media@vger.kernel.org, Hans Verkuil Subject: Re: [PATCH] uvcvideo: Don't call vb2 mmap and get_unmapped_area with queue lock held References: <1424111134-22413-1-git-send-email-laurent.pinchart@ideasonboard.com> <87k2z9558i.fsf@nemi.mork.no> Date: Mon, 09 Mar 2015 12:06:36 +0100 In-Reply-To: <87k2z9558i.fsf@nemi.mork.no> (=?utf-8?Q?=22Bj=C3=B8rn?= Mork"'s message of "Mon, 23 Feb 2015 10:47:41 +0100") Message-ID: <871tkye8g3.fsf@nemi.mork.no> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-media-owner@vger.kernel.org List-ID: Bjørn Mork writes: > Laurent Pinchart writes: > >> Bjørn, does this fix the circular locking dependency you have reported in >> "[v3.19-rc7] possible circular locking dependency in uvc_queue_streamoff" ? >> The report mentions involves locks, so I'm not 100% this patch will fix the >> issue. > > Sorry, I forgot all about that report after firing it off... Should > have followed it up with some more details. > > Grepping my logs now I cannot find this warning at all after the one I > reported. I see it once before (while running 3.19-rc6). So it is > definitely not easily reproducible. And I have a bad feeling the > trigger might involve completely unrelated USB issues... > > In any case, thanks for the patch. I will test it for a while and let > you know if the same warning shows ut with it. But based on the rare > occurence, I don't think I ever will be able to positively confirm that > the warning is gone. FWIW, I have not seen the warning after applying this patch, so it appears to fix the problem. Thanks. If I'm wrong, then I'm sure Murphy will tell us as soon as I send this email :-) Bjørn