From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B6ECC433B4 for ; Mon, 3 May 2021 13:48:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C570611CE for ; Mon, 3 May 2021 13:48:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234387AbhECNtT (ORCPT ); Mon, 3 May 2021 09:49:19 -0400 Received: from mga04.intel.com ([192.55.52.120]:64831 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232195AbhECNtL (ORCPT ); Mon, 3 May 2021 09:49:11 -0400 IronPort-SDR: +FYjd2KjCYWOxdIUG1E2LD2LhxV5vUkD7e1sbjRyRDVM8EsRYT++rsVCyTCtiFyagxjp4QE+ma Rpj3f+KMGtbw== X-IronPort-AV: E=McAfee;i="6200,9189,9973"; a="195687448" X-IronPort-AV: E=Sophos;i="5.82,270,1613462400"; d="scan'208";a="195687448" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 May 2021 06:48:17 -0700 IronPort-SDR: +xSVnXJbRHsNB+axtW3WmD08iqybp6Qsy2ImH6A/U3h1BkB6kRCmgkqZUW27E1G89RylIp9lXf oC5uYYkfK2mw== X-IronPort-AV: E=Sophos;i="5.82,270,1613462400"; d="scan'208";a="530517064" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 May 2021 06:48:13 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1ldYvi-009HHh-Ku; Mon, 03 May 2021 16:48:10 +0300 Date: Mon, 3 May 2021 16:48:10 +0300 From: Andy Shevchenko To: Frieder Schrempf Cc: Marc Kleine-Budde , linux-can@vger.kernel.org, Wolfgang Grandegger , "David S. Miller" , Jakub Kicinski , Liam Girdwood , Mark Brown , Vincent Mailhol , Oliver Hartkopp , Timo =?iso-8859-1?B?U2NobPzfbGVy?= , Tim Harvey , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Null pointer dereference in mcp251x driver when resuming from sleep Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, May 03, 2021 at 04:44:24PM +0300, Andy Shevchenko wrote: > On Mon, May 03, 2021 at 03:11:40PM +0200, Frieder Schrempf wrote: > > Hi, > > > > with kernel 5.10.x and 5.12.x I'm getting a null pointer dereference > > exception from the mcp251x driver when I resume from sleep (see trace > > below). > > > > As far as I can tell this was working fine with 5.4. As I currently don't > > have the time to do further debugging/bisecting, for now I want to at least > > report this here. > > > > Maybe there is someone around who could already give a wild guess for what > > might cause this just by looking at the trace/code!? > > Does revert of c7299fea6769 ("spi: Fix spi device unregister flow") help? Other than that, bisecting will take not more than 3-4 iterations only: % git log --oneline v5.4..v5.10.34 -- drivers/net/can/spi/mcp251x.c 3292c4fc9ce2 can: mcp251x: fix support for half duplex SPI host controllers e0e25001d088 can: mcp251x: add support for half duplex controllers 74fa565b63dc can: mcp251x: Use readx_poll_timeout() helper 2d52dabbef60 can: mcp251x: add GPIO support cfc24a0aa7a1 can: mcp251x: sort include files alphabetically df561f6688fe treewide: Use fallthrough pseudo-keyword 8ce8c0abcba3 can: mcp251x: only reset hardware as required 877a902103fd can: mcp251x: add mcp251x_write_2regs() and make use of it 50ec88120ea1 can: mcp251x: get rid of legacy platform data 14684b93019a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net -- With Best Regards, Andy Shevchenko