Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754539AbZJKXMJ (ORCPT ); Sun, 11 Oct 2009 19:12:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753761AbZJKXMG (ORCPT ); Sun, 11 Oct 2009 19:12:06 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:40001 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753748AbZJKXMG (ORCPT ); Sun, 11 Oct 2009 19:12:06 -0400 Date: Sun, 11 Oct 2009 16:07:50 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: "Rafael J. Wysocki" , David Woodhouse , Greg Kroah-Hartman cc: Linux Kernel Mailing List , Adrian Bunk , Andrew Morton , Natalie Protasevich Subject: Re: 2.6.32-rc4: Reported regressions from 2.6.31 In-Reply-To: Message-ID: References: User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1738 Lines: 40 On Mon, 12 Oct 2009, Rafael J. Wysocki wrote: > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=14374 > Subject : MCEs caused by commit db8be50c4307dac2b37305fc59c8dc0f978d09ea > Submitter : Nick Piggin > Date : 2009-10-02 7:34 (10 days old) > First-Bad-Commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=db8be50c4307dac2b37305fc59c8dc0f978d09ea > References : http://marc.info/?l=linux-kernel&m=125446885705223&w=4 I think we're going to have to just revert that commit. It's wrong. It would be nice to do USB handoff earlier, but - the correct fix is to make the damn IOMMU code to do it's thing later - the USB handoff cannot be done with just PCI config cycles, and will need to do ioremap's etc, which in turn will need the resources to be allocated, which in turn is not possible at FIXUP_HEADER time. so however much we migth _wish_ to do what that commit does, the commit is obvious crap in retrospect. The IOMMU should not be reprogrammed until _after_ we have handled and re-initialized all the devices, so I really think the problem is the IOMMU code, not the USB code. (Of course, the underlying problem is that USB legacy mode handling by BIOS with SMM is some seriously insane crap, no question about that. At the same time, the IOMMU code is just clearly wrong in removing the legacy mappings before we have initialized all devices, so the revert is simply the right thing to do) Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/