Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755122AbcLZHln convert rfc822-to-8bit (ORCPT ); Mon, 26 Dec 2016 02:41:43 -0500 Received: from mga03.intel.com ([134.134.136.65]:56002 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751222AbcLZHlm (ORCPT ); Mon, 26 Dec 2016 02:41:42 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,404,1477983600"; d="scan'208";a="206827209" From: "Du, Changbin" To: Chris Wilson CC: "Vetter, Daniel" , "airlied@linux.ie" , "intel-gfx@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" Subject: RE: [Intel-gfx] [PATCH] drm/i915: check if execlist_port is empty before using its content Thread-Topic: [Intel-gfx] [PATCH] drm/i915: check if execlist_port is empty before using its content Thread-Index: AQHSXOAbd/qOIcoMQkeDu+nQv5T4MKEUoteAgAU46fA= Date: Mon, 26 Dec 2016 07:41:36 +0000 Message-ID: <0C18FE92A7765D4EB9EE5D38D86A563A53A9C855@SHSMSX103.ccr.corp.intel.com> References: <20161223054636.3924-1-changbin.du@intel.com> <20161223075121.GB14877@nuc-i3427.alporthouse.com> In-Reply-To: <20161223075121.GB14877@nuc-i3427.alporthouse.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ctpclassification: CTP_IC x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiZTA5MTFiMmUtZmVjNS00Yzc1LWJjYTgtZTRjMDVjYmZlNjhlIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE1LjkuNi42IiwiVHJ1c3RlZExhYmVsSGFzaCI6ImRjUEo2UURqUnFlQzhDZnZZdnQzTXlsa2g5RDBnU2ZmTEtYMzFNZUZlUE09In0= x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 649 Lines: 17 > On Fri, Dec 23, 2016 at 01:46:36PM +0800, changbin.du@intel.com wrote: > > From: "Du, Changbin" > > > > This patch fix a crash in function reset_common_ring. In this case, > > the port[0].request is null when reset the render ring, so a null > > dereference exception is raised. We need to check execlist_port status > > first. > > No. The root cause is whatever got you into the illegal condition in the > first place. > -Chris > Thanks, I will restudy the code after process my current job. Since this happen on gvt guest, so this may related to gvt emulation. > -- > Chris Wilson, Intel Open Source Technology Centre