From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: Re: [PATCH] drm/i915: Mask the ring->head offset using the ring->size Date: Tue, 17 Jan 2012 11:14:04 +0000 Message-ID: References: <1320793992-2891-1-git-send-email-chris@chris-wilson.co.uk> <20120117105927.GI4093@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTP id 60A959ECE1 for ; Tue, 17 Jan 2012 03:14:15 -0800 (PST) In-Reply-To: <20120117105927.GI4093@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org, stable@kernel.org List-Id: intel-gfx@lists.freedesktop.org On Tue, 17 Jan 2012 11:59:27 +0100, Daniel Vetter wrote: > On Tue, Nov 08, 2011 at 11:13:12PM +0000, Chris Wilson wrote: > > Rather than relying on the hardware to do this correctly, we can > > trivially do it ourselves. > > > > This fixes a very reliable crash on d-i-n with all bits enabled during a > > cairo-trace replay. The symptoms of the crash is that we continue to > > write commands into the render ring buffer past the active head > > position, leading to undefined operations. > > > > Signed-off-by: Chris Wilson > > Cc: stable@kernel.org > > I guess this is just the usual "snb doesn't like being pushed to hard bug" > resulting in random crashes with confusing error_states. So I think I'll > drop this. Correct? I could find no other reason for this to have any effect other than the hw not playing fair so don't apply it until some one else starts experiencing random hangs on their SNB and can confirm whether this patch helps. -Chris -- Chris Wilson, Intel Open Source Technology Centre