From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754242Ab0IDWpF (ORCPT ); Sat, 4 Sep 2010 18:45:05 -0400 Received: from silver.sucs.swan.ac.uk ([137.44.10.1]:54172 "EHLO silver.sucs.swan.ac.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754158Ab0IDWpE (ORCPT ); Sat, 4 Sep 2010 18:45:04 -0400 Date: Sat, 4 Sep 2010 23:44:53 +0100 From: Sitsofe Wheeler To: Sven Joachim Cc: Hugh Dickins , Pekka Enberg , Chris Wilson , torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, Andrew Morton , Jesse Barnes Subject: Re: [PATCH] Revert "drm/i915: fix vblank wait test condition" Message-ID: <20100904224453.GA31664@sucs.org> References: <1283588234-2514-1-git-send-email-penberg@kernel.org> <89k83a$9hv9li@azsmga001.ch.intel.com> <87vd6ls0jd.fsf@turtle.gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87vd6ls0jd.fsf@turtle.gmx.de> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Sep 04, 2010 at 10:42:46PM +0200, Sven Joachim wrote: > On 2010-09-04 21:54 +0200, Hugh Dickins wrote: > > > On Sat, 4 Sep 2010, Pekka Enberg wrote: > >> On Sat,  4 Sep 2010 11:17:14 +0300, Pekka Enberg wrote: > >> >> This reverts commit 9559fcdbff4f93d29af04478bbc48294519424f5. The commit causes > >> >> wrong screen resolution on some i915 machines such as MacBook which is a > >> >> regression from 2.6.35. The issue has been reported multiple times but no fix > >> >> has emerged: > >> > >> On Sat, Sep 4, 2010 at 12:21 PM, Chris Wilson wrote: > >> > NAK. You can't simply hide one bug by introducing a much bigger one. > >> > >> Dude, it's a nasty regression from 2.6.35. What exactly are you NAK'ing here? > >> > >> > As you have an affected machine, find which wait_for_vblank() needs to be > >> > replaced with a msleep(20|50). > >> > >> The attached patch fixes things here. I'm not a drm developer so I > >> don't know if it makes technical sense. > > > > Many thanks to you, Pekka: I also don't know if it makes technical sense, > > but it solves the same issue for me, so I can at last use 2.6.36-rc on > > this laptop. > > Helps for me as well, but I cannot judge whether it makes technical > sense either. Thanks, Pekka! Sadly this doesn't help my EeePC 900 with an i915 when it is booted with a battery inside or after doing a suspend to ram (running modetest/xrandr in these situations says VGA is connected when there isn't even a cable attached). -- Sitsofe | http://sucs.org/~sits/