From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753837AbZBNWOx (ORCPT ); Sat, 14 Feb 2009 17:14:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751417AbZBNWOo (ORCPT ); Sat, 14 Feb 2009 17:14:44 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:56490 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752145AbZBNWOo (ORCPT ); Sat, 14 Feb 2009 17:14:44 -0500 Date: Sat, 14 Feb 2009 23:14:29 +0100 From: Ingo Molnar To: Andres Salomon Cc: Chris Ball , Harvey Harrison , Andrew Morton , LKML , "H. Peter Anvin" , Thomas Gleixner Subject: Re: [PATCH] olpc: fix model detection without OFW Message-ID: <20090214221429.GB5200@elte.hu> References: <1222208409.16003.25.camel@brick> <20090213231900.4f22008a@ephemeral> <20090214214312.GB31928@elte.hu> <20090214165311.5cf5b8bf@ephemeral> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090214165311.5cf5b8bf@ephemeral> 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 * Andres Salomon wrote: > On Sat, 14 Feb 2009 22:43:12 +0100 > Ingo Molnar wrote: > [...] > > > > Applied to tip:x86/urgent [for v2.6.29], thanks guys! > > > > Did i get the impact-line below right? > > > > Ingo > > > > More like - > > Impact: garbled display, laptop is unusable > > ;) ah, okay :-) Serious regression that warrants urgent upstream routing. > The DCON detection code determines whether there's a DCON attached > based upon the model (any XO model >= B2 is assumed to have a DCON). > The LXFB driver determines which mode to use based upon whether or not > it thinks there's a DCON attached, and the DCON/LXFB can't deal w/ > standard modes. > > So, the result is that LXFB attempts to use some random standard mode > rather than the DCON-required 1200x900, and the display is unusable. Where did my git grepping skills go wrong? I git-grepped the code and this is the scope i found: olpc_platform_info.boardrev is used for: - a printk - olpc_board_at_least() which is used in: - drivers/input/mouse/hgpk.c: mouse driver quirk - sound/pci/cs5535audio/cs5535audio_olpc.c: audio quirk aha. I missed this roundabout impact: - arch/x86/kernel/olpc.c: OLPC_F_DCON flag - which is used in olpc_has_dcon(), which is used in: - drivers/video/geode/gxfb_core.c: GX modes db [ouch if this goes wrong!] - drivers/video/geode/lxfb_core.c: ditto So i guess the mouse and audio quirk point was correct too, but the major impact is the graphics mode array mismatch and the resulting nonsensical mode setting, right? Ingo