From patchwork Sun Apr 8 23:19:11 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Larry Finger X-Patchwork-Id: 10616 Received: from mail.tu-berlin.de ([130.149.7.33]) by www.linuxtv.org with esmtp (Exim 4.72) (envelope-from ) id 1SH1PX-0002gH-QW for patchwork@linuxtv.org; Mon, 09 Apr 2012 01:20:43 +0200 X-tubIT-Incoming-IP: 209.132.180.67 Received: from vger.kernel.org ([209.132.180.67]) by mail.tu-berlin.de (exim-4.75/mailfrontend-3) with esmtp for id 1SH1PX-0001lb-Dw; Mon, 09 Apr 2012 01:20:43 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756191Ab2DHXTe (ORCPT ); Sun, 8 Apr 2012 19:19:34 -0400 Received: from mail-iy0-f174.google.com ([209.85.210.174]:60844 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751615Ab2DHXTd (ORCPT ); Sun, 8 Apr 2012 19:19:33 -0400 Received: by iagz16 with SMTP id z16so5222702iag.19 for ; Sun, 08 Apr 2012 16:19:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:x-mailer; bh=UTjT47kXArBBpa54HJ5Qy7zdYXaRBO+dTmsD4XluIPo=; b=fsmLssGTuCoz2s1p4XeA2X4jeUrtuK+/XJSyU60wsRxFZMWN4moiXPXROEcLwcPM7q PLAAFE047zf1XtXYfgYhXBYolAzcskluEwkIckqctPlCmnKj4gX6B+ktPeOcJZuXiH6g NxheGnr6DrQdIS4QauO2qX1BzFzXnjMALb9LJBc+AGm7VOKSw9gkEa4Zw4gYu2HgNt9A 5TQYYMx/u6aSGrazvPHFErWZcGsEKf1KlnQiA/2FogzkQm6FJt+uY/uMVjHnhhVzDiuP VGbex7RlHUcVbFuT7qIUQfcH7z9aE8xy6tFI3KhKHqTlXGAs4CDG3w1h1OAWTG+IEOBJ 3Zmw== Received: by 10.50.156.229 with SMTP id wh5mr3575355igb.28.1333927172799; Sun, 08 Apr 2012 16:19:32 -0700 (PDT) Received: from larrylap.site (CPE-75-81-36-228.kc.res.rr.com. [75.81.36.228]) by mx.google.com with ESMTPS id k8sm31165324igz.4.2012.04.08.16.19.31 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 08 Apr 2012 16:19:31 -0700 (PDT) From: Larry Finger To: Mauro Carvalho Chehab Cc: Larry Finger , Hans Verkuil , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, jrh Subject: [PATCH] media: au0828: Convert BUG_ON to WARN_ONCE Date: Sun, 8 Apr 2012 18:19:11 -0500 Message-Id: <1333927151-13014-1-git-send-email-Larry.Finger@lwfinger.net> X-Mailer: git-send-email 1.7.10 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-PMX-Version: 5.6.1.2065439, Antispam-Engine: 2.7.2.376379, Antispam-Data: 2012.4.8.231222 X-PMX-Spam: Gauge=IIIIIIII, Probability=8%, Report=' MULTIPLE_RCPTS 0.1, HTML_00_01 0.05, HTML_00_10 0.05, BODYTEXTP_SIZE_3000_LESS 0, BODY_SIZE_1400_1499 0, BODY_SIZE_2000_LESS 0, BODY_SIZE_5000_LESS 0, BODY_SIZE_7000_LESS 0, DATE_TZ_NA 0, DATE_TZ_NEG_0500 0, URI_ENDS_IN_HTML 0, __ANY_URI 0, __CP_MEDIA_BODY 0, __CP_URI_IN_BODY 0, __HAS_MSGID 0, __HAS_X_MAILER 0, __HAS_X_MAILING_LIST 0, __MIME_TEXT_ONLY 0, __MULTIPLE_RCPTS_CC_X2 0, __SANE_MSGID 0, __TO_MALFORMED_2 0, __URI_NS ' 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. Signed-off-by: Larry Finger --- drivers/media/video/au0828/au0828-video.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/media/video/au0828/au0828-video.c b/drivers/media/video/au0828/au0828-video.c index 0b3e481..5c53e38 100644 --- a/drivers/media/video/au0828/au0828-video.c +++ b/drivers/media/video/au0828/au0828-video.c @@ -891,8 +891,13 @@ static int res_locked(struct au0828_dev *dev, unsigned int bit) static void res_free(struct au0828_fh *fh, unsigned int bits) { struct au0828_dev *dev = fh->dev; + unsigned int bits2 = fh->resources & bits; - BUG_ON((fh->resources & bits) != bits); + if (bits2 != bits) { + WARN_ONCE(true, "au0828: Trying to free resource 0x%x" + " without reserving it\n", bits); + return; + } mutex_lock(&dev->lock); fh->resources &= ~bits;