From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754732Ab2DICQv (ORCPT ); Sun, 8 Apr 2012 22:16:51 -0400 Received: from mail-iy0-f174.google.com ([209.85.210.174]:33910 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754080Ab2DICQt (ORCPT ); Sun, 8 Apr 2012 22:16:49 -0400 Message-ID: <4F82468E.5000308@lwfinger.net> Date: Sun, 08 Apr 2012 21:16:46 -0500 From: Larry Finger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120312 Thunderbird/11.0 MIME-Version: 1.0 To: Devin Heitmueller CC: Mauro Carvalho Chehab , Hans Verkuil , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, jrh Subject: Re: [PATCH] media: au0828: Convert BUG_ON to WARN_ONCE References: <1333927151-13014-1-git-send-email-Larry.Finger@lwfinger.net> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/08/2012 08:46 PM, Devin Heitmueller wrote: > On Sun, Apr 8, 2012 at 7:19 PM, Larry Finger wrote: >> In the mail thread at http://www.mythtv.org/pipermail/mythtv-users/2012-April/331164.html, >> a kernel crash is triggered when trying to run mythtv with a HVR950Q tuner. >> The crash condition is due to res_free() being called to free something that >> has is not reserved. The actual reason for this mismatch of reserve/free is >> not known; however, using a BUG_ON rather than a WARN_ON seems unfortunate. > > This patch should be nack'd. The real reason should be identified, > and a patch should be submitted for that (and from what I gather, it > seems like it is easily reproduced by the submitter). Just add a few > "dump_stack()" calls in the res_get() and res_free() calls to identify > the failing call path. I agree that we need to find the real cause; however, I am not the one with the problem, and I do not have the hardware. In addition, I am not sure how much additional debug information the person will be able to provide. He has not built Linux kernels since 1.2. If he can get a kernel built, then we will try to find the real cause. In any case, why the reluctance to get rid of the BUG_ON? Is this condition so severe that the kernel needs to be stopped immediately? Larry