Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754943Ab3JXMRQ (ORCPT ); Thu, 24 Oct 2013 08:17:16 -0400 Received: from server109-228-6-235.live-servers.net ([109.228.6.235]:15176 "EHLO fireflyinternet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754355Ab3JXMRP (ORCPT ); Thu, 24 Oct 2013 08:17:15 -0400 X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.73.22; Date: Thu, 24 Oct 2013 13:17:06 +0100 From: Chris Wilson To: Chuansheng Liu Cc: daniel.vetter@ffwll.ch, airlied@linux.ie, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, fei.li@intel.com Subject: Re: drm/i915: Avoid accessing the stolen address when it is unavailable Message-ID: <20131024121706.GB3233@nuc-i3427.alporthouse.com> Mail-Followup-To: Chris Wilson , Chuansheng Liu , daniel.vetter@ffwll.ch, airlied@linux.ie, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, fei.li@Intel.com References: <1382632427.26153.94.camel@cliu38-desktop-build> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1382632427.26153.94.camel@cliu38-desktop-build> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1079 Lines: 28 On Fri, Oct 25, 2013 at 12:33:47AM +0800, Chuansheng Liu wrote: > > In our platform, we hit the the stolen region initialization failure case, > such as below log: > [drm:i915_stolen_to_physical] *ERROR* conflict detected with stolen region: [0x7b000000] > > And it causes the dev_priv->mm.stolen_base is NULL, in this case, we should > avoid accessing it any more. > > Here is possible call trace: > intel_enable_gt_powersave -- > > valleyview_enable_rps -- > > valleyview_setup_pctx The two create_stolen routines are no-ops in that case so all that happens instead is that we read VLV_PCBR. However, really if i915_gem_object_create_stolen_for_preallocated() fails we should abort loading the driver as it means we have a hardware conflict and undefined behaviour. -Chris -- Chris Wilson, Intel Open Source Technology Centre -- 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/