From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932189AbXDPGbg (ORCPT ); Mon, 16 Apr 2007 02:31:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754019AbXDPGbg (ORCPT ); Mon, 16 Apr 2007 02:31:36 -0400 Received: from mx1.redhat.com ([66.187.233.31]:35458 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754020AbXDPGbf (ORCPT ); Mon, 16 Apr 2007 02:31:35 -0400 Date: Mon, 16 Apr 2007 02:29:21 -0400 From: Dave Jones To: Adrian Bunk Cc: Linus Torvalds , Andrew Morton , Linux Kernel Mailing List , Jeremy Fitzhardinge , Richard Purdie Subject: Re: [2/2] 2.6.21-rc7: known regressions Message-ID: <20070416062921.GB7528@redhat.com> Mail-Followup-To: Dave Jones , Adrian Bunk , Linus Torvalds , Andrew Morton , Linux Kernel Mailing List , Jeremy Fitzhardinge , Richard Purdie References: <20070416003723.GM3691@stusta.de> <20070416005446.GB21217@redhat.com> <20070416011636.GO3691@stusta.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070416011636.GO3691@stusta.de> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 16, 2007 at 03:16:37AM +0200, Adrian Bunk wrote: > On Sun, Apr 15, 2007 at 08:54:46PM -0400, Dave Jones wrote: > > On Mon, Apr 16, 2007 at 02:37:23AM +0200, Adrian Bunk wrote: > > > > > Subject : ThinkPad X60: resume no longer works (PCI related?) > > > workaround: booting with "hpet=disable" > > > References : http://lkml.org/lkml/2007/3/13/3 > > > Submitter : Dave Jones > > > Jeremy Fitzhardinge > > > Caused-By : PCI merge > > > commit 78149df6d565c36675463352d0bfe0000b02b7a7 > > > Handled-By : Eric W. Biederman > > > Rafael J. Wysocki > > > Status : unknown > > > > note that this workaround doesn't seem to work in all cases. > > Mine may a slightly different model (I have the tablet version) > > but disabling hpet shows the same regression. > > I've been fighting Eric's USB debug cable code in the hope > > of getting _something_ useful out of it other than a black screen, > > but I've been getting nowhere with it. > > I'm not sure why I thought you two ran into the same regression. I'm not sure why I never hit the same bug that Jeremy did (again, maybe subtle hardware differences between our models), but I finally got somewhere. -rc7 with the same config I've been testing exhibited exactly the same bug. Disabling the FB_BACKLIGHT option (and all the FB drivers that 'select' it), I get a working display on resume again. This makes a lot of sense. As before, when I resumed, the backlight wasn't coming back on, but I knew the machine was alive, as capslock was working. (Amusingly, I never noticed the backlight wasn't coming back on until tonight, when I started debugging this with the lights off. Late-night debugging ftw). I'll try and narrow down exactly where it's failing in the backlight code next, but it's getting late here, so I may leave this until tomorrow for further investigation. Some other clues for anyone playing along at home: This X60 has Intel graphics. ie, I'm not using any of the drivers that 'select FB_BACKLIGHT', so somewhere in the common fb code is code that I'm guessing is dependant upon the framebuffer driver doing something or other if FB_BACKLIGHT is set. (Adding Richard to Cc: as he seems to be responsible for the FB backlight code from what I can tell.) Dave -- http://www.codemonkey.org.uk