From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261451AbUHWLPm (ORCPT ); Mon, 23 Aug 2004 07:15:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261375AbUHWLPm (ORCPT ); Mon, 23 Aug 2004 07:15:42 -0400 Received: from delerium.kernelslacker.org ([81.187.208.145]:50142 "EHLO delerium.codemonkey.org.uk") by vger.kernel.org with ESMTP id S262085AbUHWLPO (ORCPT ); Mon, 23 Aug 2004 07:15:14 -0400 Date: Mon, 23 Aug 2004 12:13:15 +0100 From: Dave Jones To: matthias brill Cc: Alan Cox , Jeremy Fitzhardinge , linux-kernel , cpufreq list Subject: Re: banias with different (unusual?) model_name Message-ID: <20040823111315.GA1589@redhat.com> Mail-Followup-To: Dave Jones , matthias brill , Alan Cox , Jeremy Fitzhardinge , linux-kernel , cpufreq list References: <20040820093344.GA2923@akamail.com> <1093008335.30968.32.camel@localhost.localdomain> <20040821115316.GA2582@akamail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040821115316.GA2582@akamail.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 21, 2004 at 01:53:16PM +0200, matthias brill wrote: > if i understand correctly, the type of the cpu can be determined by > looking at the family, model and stepping -- assuming that these values > are reported directly by the CPUID (0FA2) instruction. download the source for x86info sometime, and look at the hoops it jumps through to determine what cpu its running on. It isn't just as simple as a few cpuid calls any more. These days there are typically up to a half dozen factors that you need to look at to discriminate between possibilities. One of these, is cpu speed. Unfortunatly, as we could have booted off mains, and hence a lower clock speed, we can't do any runtime calculation like we do with bogomips/jiffies, so we have to resort to looking at the model name supplied by the BIOS. > the BIOS supplied model_name string in speedstep-centrino.c is parsed to > get the clock cycle time of the cpu. is this actually supposed to be > the "right" way (or worse: the only way) to get this information? It's pretty much all we have that we can trust. If we could do something else, I'd love to, as I distrust the abilities of BIOS programmers as much as anyone else. Dave