From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932325AbXCSPIV (ORCPT ); Mon, 19 Mar 2007 11:08:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932419AbXCSPIV (ORCPT ); Mon, 19 Mar 2007 11:08:21 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:40490 "EHLO amd.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932325AbXCSPIU (ORCPT ); Mon, 19 Mar 2007 11:08:20 -0400 Date: Mon, 19 Mar 2007 16:07:53 +0100 From: Pavel Machek To: Tim Gardner Cc: linux-kernel@vger.kernel.org Subject: Re: Suspend to RAM fault in VT when resuming Message-ID: <20070319150753.GC1915@elf.ucw.cz> References: <45F709F2.80504@canonical.com> <20070313212457.GD12370@elf.ucw.cz> <45F752EF.6030701@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <45F752EF.6030701@canonical.com> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.11+cvs20060126 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue 2007-03-13 19:42:07, Tim Gardner wrote: > Pavel Machek wrote: > > Hi1 > > > >> I've chased one of the 'Suspend to RAM' resume problems to a specific > >> line in drivers/char/vt.c, see attached 2.6.21-rc3 diff with > > > > Has suspend/resume ever worked on that hardware? > > > >> TRACE_RESUME() instrumentation. The macro scr_writew resolves to '*addr > >> = val', which appears to be causing the problem. I've verified that the > >> pointer is not NULL, but don't know if its really valid. Its pretty > >> tough to tell what is happening, but on a Dell XPS it just hangs. A Dell > >> Precision blinks the keyboard lights. > > > > It is possible that video is not initialized at that point, and that > > hardware goes seriously unhappy when you access non-existing vga. Does > > it resume ok when you completely disable video support? > > Resume works on the Dell XPS with the Ubuntu Edgy release > Ubuntu-2.6.17-10.25 (2.6.17 plus a zillion fixes). Ubuntu's git tree is > rsync://rsync.kernel.org/pub/scm/linux/kernel/git/bcollins/ubuntu-2.6.git. > Ubuntu-2.6.17-8.21 is the first version where resume works, but there > are a boatload of changes in ACPI and SW suspend between that and the > previous tag Ubuntu-2.6.17-7.20. I don't know what made SW suspend work, > but even knowing that won't tell me what broke it again. > > I've been avoiding the bisect process because it is quite time consuming > on my slow machine, there is much branch weirdness, and I'm not that > good with git. I thought if I narrowed the failure down to a small chunk > of code in 2.6.21-rc3, then the answer might be obvious. No such luck, huh? > > This crash behaves like the video memory space has become unmapped. Is > that possible? That seems improbable. It is physical ram, we do not unmap that.. -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html