Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754664Ab0BRS2n (ORCPT ); Thu, 18 Feb 2010 13:28:43 -0500 Received: from e34.co.us.ibm.com ([32.97.110.152]:46990 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752256Ab0BRS2j (ORCPT ); Thu, 18 Feb 2010 13:28:39 -0500 Date: Thu, 18 Feb 2010 10:28:20 -0800 From: "Darrick J. Wong" To: Len Brown Cc: Matthew Garrett , Ingo Molnar , davej@redhat.com, Thomas Renninger , linux-kernel , cpufreq@vger.kernel.org, linux-acpi@vger.kernel.org Subject: Re: [PATCH v2] acpi: Fix regression where _PPC is not read at boot even when ignore_ppc=0 Message-ID: <20100218182820.GQ29569@tux1.beaverton.ibm.com> Reply-To: djwong@us.ibm.com References: <20090430095414.GA19462@srcf.ucam.org> <20090430111042.GA12809@elte.hu> <20090430111338.GA21297@srcf.ucam.org> <20090515191219.GH6968@plum> <20090602232108.GG7917@plum> <20090607100541.GJ31286@elte.hu> <20090715003207.GA5111@plum> <20100216220707.GA5966@srcf.ucam.org> <20100216222611.GP29569@tux1.beaverton.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2095 Lines: 55 On Thu, Feb 18, 2010 at 04:02:39AM -0500, Len Brown wrote: > > On Tue, Feb 16, 2010 at 10:07:07PM +0000, Matthew Garrett wrote: > > > Did this ever get picked up? > > > > Nope. I vaguely recall asking a few times if there were any objections left, > > but there weren't any, and I think Len or someone said it looked good back at > > LPC last summer. Does not appear in 2.6.33-rc8 though. > > does it have a bugzilla entry? (as regressions tend to, thanks to rafael) > I don't see this in my mailbox anymore. Nope, no bugzilla entry. Do I need to create one now? A patch resend follows. --D --- Earlier, Ingo Molnar posted a patch to make it so that the kernel would avoid reading _PPC on his broken T60. Unfortunately, it seems that with Thomas Renninger's patch last July to eliminate _PPC evaluations when the processor driver loads, the kernel never actually reads _PPC at all! This is problematic if you happen to boot your non-T60 computer in a state where the BIOS _wants_ _PPC to be something other than zero. So, put the _PPC evaluation back into acpi_processor_get_performance_info if ignore_ppc isn't 1. Signed-off-by: Darrick J. Wong --- drivers/acpi/processor_perflib.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index 2cabadc..a959f6a 100644 --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -413,7 +413,11 @@ static int acpi_processor_get_performance_info(struct acpi_processor *pr) if (result) goto update_bios; - return 0; + /* We need to call _PPC once when cpufreq starts */ + if (ignore_ppc != 1) + result = acpi_processor_get_platform_limit(pr); + + return result; /* * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that -- 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/