From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754153Ab3ARTHJ (ORCPT ); Fri, 18 Jan 2013 14:07:09 -0500 Received: from cavan.codon.org.uk ([93.93.128.6]:45164 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752770Ab3ARTHH (ORCPT ); Fri, 18 Jan 2013 14:07:07 -0500 Date: Fri, 18 Jan 2013 19:06:59 +0000 From: Matthew Garrett To: Borislav Petkov , "Gopalakrishnan, Aravind" , "rjw@sisk.pl" , Andre Przywara , "cpufreq@vger.kernel.org" , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Andreas Subject: Re: [PATCH] drivers/cpufreq: Warn user when powernow-k8 tries to fall back to acpi-cpufreq and it is unavailable. Message-ID: <20130118190659.GB16757@srcf.ucam.org> References: <1357780161-30581-1-git-send-email-Aravind.Gopalakrishnan@amd.com> <20130111144940.GB21882@liondog.tnic> <20130111165054.GD10751@liondog.tnic> <4923C2DE085EEB4FAB1D375DD09D0BA6100CF170@sausexdag04.amd.com> <20130117115436.GA3853@pd.tnic> <20130118162347.GA31499@srcf.ucam.org> <20130118170755.GB4062@pd.tnic> <20130118190021.GD4062@pd.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130118190021.GD4062@pd.tnic> User-Agent: Mutt/1.5.20 (2009-06-14) 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, Jan 18, 2013 at 08:00:21PM +0100, Borislav Petkov wrote: > ################################################################################## > # x86 drivers. > # Link order matters. K8 is preferred to ACPI because of firmware bugs in early > # K8 systems. > ... > > Great. :( The only case I can see this hitting would be if the platform is using system IO rather than fixed hardware functionality. Easiest thing to do there would be something like this: diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c index 0d048f6..8b466d5 100644 --- a/drivers/cpufreq/acpi-cpufreq.c +++ b/drivers/cpufreq/acpi-cpufreq.c @@ -762,6 +762,11 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy) switch (perf->control_register.space_id) { case ACPI_ADR_SPACE_SYSTEM_IO: + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) { + pr_debug("Old AMD systems must use native drivers\n"); + result = -ENODEV; + goto err_unreg; + } pr_debug("SYSTEM IO addr space\n"); data->cpu_feature = SYSTEM_IO_CAPABLE; break; -- Matthew Garrett | mjg59@srcf.ucam.org