From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753500Ab2APHy2 (ORCPT ); Mon, 16 Jan 2012 02:54:28 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:43581 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753464Ab2APHyL (ORCPT ); Mon, 16 Jan 2012 02:54:11 -0500 Date: Mon, 16 Jan 2012 08:53:48 +0100 From: Ingo Molnar To: Michael D Labriola , Matthew Garrett Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org, Kushal Koolwal , support@versalogic.com, michael.d.labriola@gmail.com Subject: Re: Reboot hangs on VersaLogic Ocelot Message-ID: <20120116075348.GF15641@elte.hu> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=AWL,BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.0 AWL AWL: From: address is in the auto white-list Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (Cc:-ed Matthew Garrett) * Michael D Labriola wrote: > I've been troubleshooting a VersaLogic Ocelot SBC that's been > hanging on reboot ever since I upgraded its BIOS. The > conclusion I've come to is that commit e19e074 (x86: Fix > reboot problem on VersaLogic Menlow boards) needs to be > reverted. > > My system was rebooting fine (kernel v3.2) prior to upgrading > the BIOS, but it turns out that the DMI string being looked > for in the VersaLogic reboot quirk wasn't added until I > upgraded the BIOS. > > Here's a summary of the behavior I encountered on my system > (VL-EPMs-21a rev 1.00 w/ BIOS 6.5.102) > > - v2.6.37 reboot=bios is needed > > - v2.6.38-rc1: behavior changed, reboot=acpi is needed, reboot=kbd and > reboot=bios result in system hang. > > - v2.6.38: VersaLogic patch (e19e074 x86: Fix reboot problem on > VersaLogic Menlow boards) was applied prior to v2.6.38-rc7. This > patch sets a quirk for VersaLogic Menlow boards that forces the use > of reboot=bios, which doesn't work anymore. As far as I can tell, > there's no way to override this faulty quirk, as it seems to take > precedence over the reboot= argument. That's another bug i'd argue - the user specifying something on the boot command line should *always* override the kernel's built-in defaults. > - v3.2: It seems that commit 660e34c (x86: Reorder reboot method > preferences) changed the default reboot method to acpi prior to > v3.0-rc1, which means the default behavior is appropriate for the > Ocelot. After reverting commit e19e074, my system reboots perfectly > w/out passing any reboot= arguments. I confirmed that this is a > true statement for all 3 versions of the Ocelot's BIOS. And this works for the older BIOS version as well, the one which motivated commit e19e074? Please send a patch that removes the quirk (not named a revert - as technically the old quirk did solve problems), with the changelog containing your (excellent) bug analysis and the test coverage above, plus a signoff? Matthew, do you concur? Looks like your reordering changes actively improved the default behavior and we can start removing quirks. Thanks, Ingo