From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760019Ab1LPCM5 (ORCPT ); Thu, 15 Dec 2011 21:12:57 -0500 Received: from one.firstfloor.org ([213.235.205.2]:37187 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751084Ab1LPCM4 (ORCPT ); Thu, 15 Dec 2011 21:12:56 -0500 Date: Fri, 16 Dec 2011 03:12:54 +0100 From: Andi Kleen To: "H. Peter Anvin" Cc: Andi Kleen , Borislav Petkov , linux-kernel@vger.kernel.org, kay.sievers@vrfy.org, trenn@suse.de, Andi Kleen , davej@redhat.com Subject: Re: [PATCH 07/10] cpufreq: Add support for x86 cpuinfo auto loading Message-ID: <20111216021254.GG14839@one.firstfloor.org> References: <1323304882-27953-1-git-send-email-andi@firstfloor.org> <1323304882-27953-8-git-send-email-andi@firstfloor.org> <20111208084958.GA23245@gere.osrc.amd.com> <20111208143725.GD24062@one.firstfloor.org> <4EEA9CB2.9020709@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4EEA9CB2.9020709@zytor.com> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 15, 2011 at 05:19:46PM -0800, H. Peter Anvin wrote: > On 12/08/2011 06:37 AM, Andi Kleen wrote: > >> Well, there is CPUID_8000_0007_EDX[7] which denotes the presence > >> of the P-state registers. It probably could be added to > >> init_scattered_cpuid_features() but there's still special handling > >> needed for K8. > > > > Dave is probably right that it's not worth moving the list. > > > >> Can you do both a family and a feature bit test with the autoprobing > >> code? > > > > Another similar question: is it possible to key a load on more than one > CPU feature? It's fairly common that you need more than one feature for > a specific piece of code to function, and it would be good to be able to > represent it. Right now it's not possible. The driver just errors out if it can't find some additional capability. I considered it originally, but all the cases I looked at were quite obscure (unlikely to happen) so I opted for this simpler setup. -Andi