From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757457Ab1LHBYj (ORCPT ); Wed, 7 Dec 2011 20:24:39 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48937 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753166Ab1LHBYi (ORCPT ); Wed, 7 Dec 2011 20:24:38 -0500 Date: Wed, 7 Dec 2011 20:24:29 -0500 From: Dave Jones To: Andi Kleen Cc: linux-kernel@vger.kernel.org, kay.sievers@vrfy.org, trenn@suse.de, Andi Kleen , hpa@zytor.com Subject: Re: [PATCH 07/10] cpufreq: Add support for x86 cpuinfo auto loading Message-ID: <20111208012429.GC27892@redhat.com> Mail-Followup-To: Dave Jones , Andi Kleen , linux-kernel@vger.kernel.org, kay.sievers@vrfy.org, trenn@suse.de, Andi Kleen , hpa@zytor.com References: <1323304882-27953-1-git-send-email-andi@firstfloor.org> <1323304882-27953-8-git-send-email-andi@firstfloor.org> <20111208010730.GB27892@redhat.com> <20111208011356.GA24062@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111208011356.GA24062@one.firstfloor.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 08, 2011 at 02:13:56AM +0100, Andi Kleen wrote: > > This makes e_powersaver bind to every family 6 VIA cpu. > > But the old logic only bound to certain models. > > Won't this will clash with this other driver if both are built ? > > The code does > > static int __init eps_init(void) > { > if (!x86_match_cpu(eps_cpu_id) || boot_cpu_data.x86_model < 10) > return -ENODEV; > > So modprobe will load it, but if the CPU is too old it will just error out > again. I think that's reasonable. There's no direct way current > to express a >= in the matches because modprobe uses fnmatch() > > Also most likely the old CPUs won't have the EST bit anyways, then > it won't even be loaded. I don't have any VIA CPUs to check any more, and my memory is a little vague, but I think you're right on this assumption. > > iirc, the intention here was longhaul on cpus that don't have EST, > > and e_powersaver on those that do. Maybe an additional check for the > > absense of EST in longhaul's init code would do the trick. > > (sidenote: I don't recall why we even have e-powersaver, instead of them > > just using acpi-cpufreq). > > It's not done today, but I could add it. > > But I tried to keep the existing behaviour. > This matches this. I have no way to test these CPUs so I would > prefer to be as compatible as possible. That's fine. Don't sweat it for this, it's something that could be done later if someone cares enough. We might have a hard time finding someone even still using this driver. > AFAIK distros just load them all right? In Fedora, we used to. In F16, we changed things so instead of a monstrous init script with nested if's and a whole bunch of hairy logic, we changed all the modules to be built-in's, and relied on the link-order in the cpufreq Makefile to satisfy the 'first to bind wins'. Yes, ugly, but we didn't have this patchset ;-) Dave