Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761786AbXLMKda (ORCPT ); Thu, 13 Dec 2007 05:33:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758458AbXLMKdV (ORCPT ); Thu, 13 Dec 2007 05:33:21 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:51275 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758267AbXLMKdU (ORCPT ); Thu, 13 Dec 2007 05:33:20 -0500 Subject: Re: 2.6.24-rc5 "videobuf_read_start" [drivers/media/video/videobuf-dvb.ko] undefined! From: Mauro Carvalho Chehab To: Jean Delvare Cc: Adrian Bunk , Shane , Brandon Philips , linux-kernel@vger.kernel.org, video4linux-list In-Reply-To: <20071212231944.53f09d99@hyperion.delvare> References: <20071212090709.GF14204@stusta.de> <1197457394.4807.40.camel@gaivota> <20071212120308.GG14204@stusta.de> <1197469316.4744.22.camel@gaivota> <20071212231944.53f09d99@hyperion.delvare> Content-Type: text/plain; charset=utf-8 Date: Thu, 13 Dec 2007 08:33:06 -0200 Message-Id: <1197541986.4729.24.camel@gaivota> Mime-Version: 1.0 X-Mailer: Evolution 2.12.0-2mdv2008.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1414 Lines: 39 Em Qua, 2007-12-12 às 23:19 +0100, Jean Delvare escreveu: > Hi Mauro, > > On Wed, 12 Dec 2007 12:21:56 -0200, Mauro Carvalho Chehab wrote: > > What happened is that changeset 19bc5133dae9562e8824ef101464061f9854c1d8 > > fixed some bad locks. > > > > After this changeset, videobuf_read_stream() holds q->lock and calls > > videobuf_read_start(). To avoid waiting forever for the lock to be > > released, he removed the mutex from videobuf_read_start with this line > > [1]: > > > > - err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR); > > + err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR); > > > > So, after the patch, videobuf_read_start() can't be safely called. So, > > just adding EXPORT_SYMBOL_GPL() breaks videobuf-dvb at runtime. > > > > The proper solution is provided by this changeset: > > http://git.kernel.org/?p=linux/kernel/git/mchehab/v4l-dvb.git;a=commitdiff;h=19fb1457990b6b7e15586ec7331541a184233acc > > There's a "static" missing in that patch: __videobuf_read_start is only > used internally. Thanks. It seems that I were not on my best day when I wrote this patch.... Fixed. -- Cheers, Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/