From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753372Ab0EQPPk (ORCPT ); Mon, 17 May 2010 11:15:40 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:50634 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751261Ab0EQPPj (ORCPT ); Mon, 17 May 2010 11:15:39 -0400 Date: Mon, 17 May 2010 08:12:59 -0700 (PDT) From: Linus Torvalds To: Andreas Herrmann cc: Yuhong Bao , venkatesh.pallipadi@intel.com, markh@compro.net, dmarkh@cfl.rr.com, andi@firstfloor.org, alain@knaff.lu, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86: Disable HPET MSI on ATI SB700/SB800 In-Reply-To: <20100517145943.GV5888@alberich.amd.com> Message-ID: References: <87bphpd4rt.fsf@basil.nowhere.org> <4B32565E.6000501@compro.net> <20091223191806.GA3336@linux-os.sc.intel.com> <4B3270FE.5090607@compro.net> <1261600243.16916.56.camel@localhost.localdomain> <4B476E8D.1030308@compro.net> <20100121190952.GA32523@linux-os.sc.intel.com> <20100125171059.GB5041@alberich.amd.com> <20100517145943.GV5888@alberich.amd.com> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) 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 On Mon, 17 May 2010, Andreas Herrmann wrote: > > FYI. I've tried to trigger the publication of errata information for that > chipset. Finally this has happened. > > The discussed problem is indeed due to an erratum. See erratum #27 in > http://support.amd.com/us/Embedded_TechDocs/46837.pdf > > The suggested workaround for this is to disable HPET MSI if LPC > devices are used. I doubt that there is a convenient way for Linux to > find out whether LPC devices are used. Thus I think the only solution > to safely avoid the problem is the currently implemented quirk to > disable HPET MSI on this chipset. Goodie. It would be good to point this out in the source too. Would you be willing to send in a patch that documents this quirk as a result of that erratum #27, so that we don't lose sight of why we're doing that odd MSI disable? Linus