From mboxrd@z Thu Jan  1 00:00:00 1970
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Subject: Re: [PATCH] drm/i915: Avoid divbyzero in modesetting
Date: Mon, 22 Feb 2016 15:56:19 +0100
Message-ID: <56CB2193.2060409@linux.intel.com>
References: <1456141948-7172-1-git-send-email-tvrtko.ursulin@linux.intel.com>
 <56CB08A0.30406@linux.intel.com> <56CB1AE0.4090204@linux.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 mga02.intel.com (mga02.intel.com [134.134.136.20])
 by gabe.freedesktop.org (Postfix) with ESMTP id EF8E76E218
 for <Intel-gfx@lists.freedesktop.org>; Mon, 22 Feb 2016 14:56:25 +0000 (UTC)
In-Reply-To: <56CB1AE0.4090204@linux.intel.com>
List-Unsubscribe: <https://lists.freedesktop.org/mailman/options/intel-gfx>,
 <mailto:intel-gfx-request@lists.freedesktop.org?subject=unsubscribe>
List-Archive: <https://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: <https://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: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>, Intel-gfx@lists.freedesktop.org
List-Id: intel-gfx@lists.freedesktop.org
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