From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754667AbYINNZv (ORCPT ); Sun, 14 Sep 2008 09:25:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753287AbYINNZn (ORCPT ); Sun, 14 Sep 2008 09:25:43 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:56781 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753211AbYINNZn (ORCPT ); Sun, 14 Sep 2008 09:25:43 -0400 Date: Sun, 14 Sep 2008 15:25:20 +0200 From: Ingo Molnar To: Frans Pop Cc: "Pallipadi, Venkatesh" , "Siddha, Suresh B" , Linux Kernel Mailing List , "arjan@linux.intel.com" , "jbarnes@virtuousgeek.org" Subject: Re: [Bug 10843] Display artifacts on XOrg logout with PAT kernel and VESA framebuffer Message-ID: <20080914132520.GA554@elte.hu> References: <200809121533.43318.elendil@planet.nl> <7E82351C108FA840AB1866AC776AEC462CA8E8B0@orsmsx505.amr.corp.intel.com> <200809131149.55472.elendil@planet.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200809131149.55472.elendil@planet.nl> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Frans Pop wrote: > On Saturday 13 September 2008, Pallipadi, Venkatesh wrote: > > >We have too many entires in PAT list due to RAM pages being marked > > >UC by drivers. Unfortunately, there are no quick fixes that can fix > > >this for 2.6.27. However, we are aware of the problem here and > > >working on a more complete fix for this. We should have the patch > > >for it soon. > > > > Can you try the patch here > > http://www.ussg.iu.edu/hypermail/linux/kernel/0809.1/2074.html > > And report back whether that resolves the issue. > > Yes, that solves the issue. The display is now free of artifacts > again, both on logout and when I switch users in X. The > pat_memtype_list looks a lot more sane too (see attachment). > > So it _was_ a regression caused by pat itself after all, and not the > result of incorrect memory handling in the framebuffer code. Could you > take over the bug report #10843 in bugzilla (it is currently assigned > to the framebuffer people) and ensure it gets closed once the patch > gets accepted in Linus' tree? ok, since those patches are only supposed to improve performance, it would be nice to know why this fixes the display artifacts. They were a rather long-living bug and we'd like to avoid such bug patterns in the future. or is it the timing effect? Too slow programming of the GX chip causes artifacts? (but i think this is not very likely) Ingo