From mboxrd@z Thu Jan  1 00:00:00 1970
From: Chris Wilson <chris@chris-wilson.co.uk>
Subject: Re: [PATCH 3/3] drm/i915: disable wc gtt pte mappings
	on gen2
Date: Wed, 10 Oct 2012 23:37:36 +0100
Message-ID: <453bf0$61is0t@azsmga001.ch.intel.com>
References: <1349903641-18378-1-git-send-email-daniel.vetter@ffwll.ch>
	<1349903641-18378-3-git-send-email-daniel.vetter@ffwll.ch>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org>
Received: from mga14.intel.com (mga14.intel.com [143.182.124.37])
	by gabe.freedesktop.org (Postfix) with ESMTP id 9F8549E8BC
	for <intel-gfx@lists.freedesktop.org>;
	Wed, 10 Oct 2012 15:38:00 -0700 (PDT)
In-Reply-To: <1349903641-18378-3-git-send-email-daniel.vetter@ffwll.ch>
List-Unsubscribe: <http://lists.freedesktop.org/mailman/options/intel-gfx>,
	<mailto:intel-gfx-request@lists.freedesktop.org?subject=unsubscribe>
List-Archive: <http://lists.freedesktop.org/archives/intel-gfx>
List-Post: <mailto:intel-gfx@lists.freedesktop.org>
List-Help: <mailto:intel-gfx-request@lists.freedesktop.org?subject=help>
List-Subscribe: <http://lists.freedesktop.org/mailman/listinfo/intel-gfx>,
	<mailto:intel-gfx-request@lists.freedesktop.org?subject=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: Intel Graphics Development <intel-gfx@lists.freedesktop.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
List-Id: intel-gfx@lists.freedesktop.org

On Wed, 10 Oct 2012 23:14:01 +0200, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> It doesn't work since the gtt pte range sits in the middle of the mmio
> bar. We didn't notice that since both my and Chris' gen2 machines
> don't support PAT and hence all wc io mapping request will
> automatically be demoted to uc.
> 
> This regression has been introduce in
> 
> commit edef7e685da05c13cce50c0126189c80fe2c8f71
> Author: Chris Wilson <chris@chris-wilson.co.uk>
> Date:   Fri Sep 14 11:57:47 2012 +0100
> 
>     agp/intel: Use a write-combining map for updating PTEs
> 
> Reported-by: Egbert Eich <eich@pdx.freedesktop.org>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=55834
> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Thanks for the explanation,
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre