From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932273Ab0EKRZz (ORCPT ); Tue, 11 May 2010 13:25:55 -0400 Received: from cavan.codon.org.uk ([93.93.128.6]:38962 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932247Ab0EKRZx (ORCPT ); Tue, 11 May 2010 13:25:53 -0400 Date: Tue, 11 May 2010 18:25:43 +0100 From: Matthew Garrett To: Linus Torvalds Cc: Len Brown , Linux Kernel Mailing List , linux-acpi@vger.kernel.org, Andrew Morton Subject: Re: [git pull request] ACPI patches for 2.6.34-rc6 Message-ID: <20100511172543.GA17868@srcf.ucam.org> References: <20100507061203.GA8779@srcf.ucam.org> <20100507211331.GA28906@srcf.ucam.org> <20100507213600.GC28906@srcf.ucam.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100507213600.GC28906@srcf.ucam.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: mjg59@cavan.codon.org.uk X-SA-Exim-Scanned: No (on cavan.codon.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 07, 2010 at 10:36:00PM +0100, Matthew Garrett wrote: > On Fri, May 07, 2010 at 02:21:08PM -0700, Linus Torvalds wrote: > > Well, is there any reason to have 'set_sci_en_on_resume' at all then? > > I'd hope not, but it depends on what Windows does on resume. If it > doesn't do the SMM call and just does the register write instead, then > it may be that some machines are on that list because the SMM call > breaks them rather than because they need the register to be set by > hand. I'm planning on instrumenting it to check, but haven't had time to > do so yet. I've now checked the behaviour of Windows. It turns out that it never makes the ACPI enable SMM call on resume. This is consistent with http://bugzilla.kernel.org/show_bug.cgi?id=13745 which shows a bug being introduced by us making the enable call in the first place. Merging my patch and removing the blacklist would re-break these machines. Instead, we should just unconditionally set SCI_EN since this is the tested configuration. I'll send a followup patch. -- Matthew Garrett | mjg59@srcf.ucam.org