From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757095Ab3ANQzn (ORCPT ); Mon, 14 Jan 2013 11:55:43 -0500 Received: from nat28.tlf.novell.com ([130.57.49.28]:58782 "EHLO nat28.tlf.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757002Ab3ANQzl convert rfc822-to-8bit (ORCPT ); Mon, 14 Jan 2013 11:55:41 -0500 Message-Id: <50F4469802000078000B57EB@nat28.tlf.novell.com> X-Mailer: Novell GroupWise Internet Agent 12.0.1 Date: Mon, 14 Jan 2013 16:55:36 +0000 From: "Jan Beulich" To: "Borislav Petkov" , "Andre Przywara" , "Stefan Bader" Cc: "xen-devel@lists.xensource.com" , "Konrad Rzeszutek Wilk" , "Matthew Garrett" , "Rafael J. Wysocki" , "Linux Kernel Mailing List" Subject: Re: [Xen-devel] kernel 3.7+ cpufreq regression on AMD system running as dom0 References: <50F42B3E.7090602@canonical.com> <20130114163445.GA4867@liondog.tnic> In-Reply-To: <20130114163445.GA4867@liondog.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>> On 14.01.13 at 17:34, Borislav Petkov wrote: > On Mon, Jan 14, 2013 at 04:58:54PM +0100, Stefan Bader wrote: >> --- a/drivers/acpi/processor_perflib.c >> +++ b/drivers/acpi/processor_perflib.c >> @@ -340,6 +340,9 @@ static void amd_fixup_frequency(struct acpi_processor_px > *px >> if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10) >> || boot_cpu_data.x86 == 0x11) { >> rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi); >> + /* Bit 63 indicates whether contents are valid */ >> + if (!(hi & 0x8000000)) >> + return; > > I don't think that's the right change - this is fixing baremetal so that > it works on xen. And besides, this code was in powernow-k8 before so I'm > wondering why did it work then. Because the driver doesn't get loaded in that case? Jan