From mboxrd@z Thu Jan  1 00:00:00 1970
From: Daniel Vetter <daniel@ffwll.ch>
Subject: Re: [PATCH] drm/i915: RMW register cycles considered
	evil
Date: Mon, 6 Jul 2015 16:58:19 +0200
Message-ID: <20150706145819.GP2156@phenom.ffwll.local>
References: <1436186522-7834-1-git-send-email-daniel.vetter@ffwll.ch>
 <20150706124619.GD19207@strange.amr.corp.intel.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64
Return-path: <intel-gfx-bounces@lists.freedesktop.org>
Received: from mail-wi0-f177.google.com (mail-wi0-f177.google.com
 [209.85.212.177])
 by gabe.freedesktop.org (Postfix) with ESMTPS id 7A9CE6E8DB
 for <intel-gfx@lists.freedesktop.org>; Mon,  6 Jul 2015 07:55:33 -0700 (PDT)
Received: by wibdq8 with SMTP id dq8so156027015wib.1
 for <intel-gfx@lists.freedesktop.org>; Mon, 06 Jul 2015 07:55:32 -0700 (PDT)
Content-Disposition: inline
In-Reply-To: <20150706124619.GD19207@strange.amr.corp.intel.com>
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>
Errors-To: intel-gfx-bounces@lists.freedesktop.org
Sender: "Intel-gfx" <intel-gfx-bounces@lists.freedesktop.org>
To: Damien Lespiau <damien.lespiau@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>, Intel Graphics Development <intel-gfx@lists.freedesktop.org>, Daniel Vetter <daniel.vetter@intel.com>
List-Id: intel-gfx@lists.freedesktop.org
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