From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752666AbZBPSN1 (ORCPT ); Mon, 16 Feb 2009 13:13:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750888AbZBPSNT (ORCPT ); Mon, 16 Feb 2009 13:13:19 -0500 Received: from mx2.suse.de ([195.135.220.15]:56484 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750732AbZBPSNS (ORCPT ); Mon, 16 Feb 2009 13:13:18 -0500 From: Thomas Renninger Organization: SUSE Products GmbH To: Matthew Garrett Subject: Re: cpuinfo shows wrong MHz value Date: Mon, 16 Feb 2009 19:13:15 +0100 User-Agent: KMail/1.10.3 (Linux/2.6.27.13-HEAD_20090130075504_71baee03-default; KDE/4.1.3; x86_64; ; ) Cc: linux-kernel@vger.kernel.org References: <200902142217.51655.jplatte@naasa.net> <20090216165008.GA8249@srcf.ucam.org> In-Reply-To: <20090216165008.GA8249@srcf.ucam.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200902161913.16021.trenn@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 16 February 2009 17:50:08 Matthew Garrett wrote: > On Mon, Feb 16, 2009 at 02:19:50PM +0000, Thomas Renninger wrote: > > > There should be a message when this driver is loaded like: > > "This driver is broken. Don't use it, don't complain." > > Please don't. It's perfectly valid (if dumb) for machines to depend on > the CPU for passive cooling even if they don't expose any P or T states. No it's not valid. If the BIOS does not export these, it could be for a reason. > In that case p4-clockmod is the only code that can manage it. The > removal of the user-visible cpufreq interface should be a strong enough > hint that it's not intended for speed control. AFAIK p4-clockmode is still not synchronized with ACPI throttling? Thus this driver will destroy a valid machine setup where the BIOS exports throttling states via ACPI. The driver is broken (and rather useless) and all the complaints about it get annoying. I wonder how dangerous it even is. If thermal management on a P4 is properly implemented via "BIOS throws high temperature MCE and throttles the CPU itself", could the p4_clockmode driver override the BIOS/HW settings and still run unthrottled? Danger! Anyway, I better do not answer on p4_clockmode complaints anymore and simply delete them, it's just a waste of time. Thomas