From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keith Packard Subject: Re: [PATCH 1/2] drm/i915: Remove use of the autoreported ringbuffer HEAD position Date: Wed, 08 Feb 2012 09:36:29 -0800 Message-ID: <867gzxfcrm.fsf@sumi.keithp.com> References: <1328708054-26350-1-git-send-email-chris@chris-wilson.co.uk> <20120208145425.GD5030@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from keithp.com (home.keithp.com [63.227.221.253]) by gabe.freedesktop.org (Postfix) with ESMTP id E654FA0956 for ; Wed, 8 Feb 2012 09:36:34 -0800 (PST) In-Reply-To: <20120208145425.GD5030@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 , Chris Wilson Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org <#part sign=pgpmime> On Wed, 8 Feb 2012 15:54:25 +0100, Daniel Vetter wrote: > I'm on the fence whether we should include this in -fixes. On one hand it > fixes a severe issue on snb, but introduces a perf regression without the > second patch. Otoh we've never shipped snb without it broken like this. > But if it turns out that this is broken on ilk and earlier, too, I think > we definitely need these two patches in -fixes. The first one is a simple bug fix -- not attempting to use the status page value. That seems reasonable for -fixes. The second one has a bunch of global changes which seems less suitable for -fixes, especially as it now requires that the driver reliably track ring positions, which seems a bit perilous to me. -- keith.packard@intel.com