From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965056Ab3BNR3q (ORCPT ); Thu, 14 Feb 2013 12:29:46 -0500 Received: from hydra.sisk.pl ([212.160.235.94]:38151 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964885Ab3BNR3o (ORCPT ); Thu, 14 Feb 2013 12:29:44 -0500 From: "Rafael J. Wysocki" To: Dirk Brandewie Cc: Viresh Kumar , Dave Jones , linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org Subject: Re: [PATCH 0/5] Add P state driver for Intel Core Processors Date: Thu, 14 Feb 2013 18:36:13 +0100 Message-ID: <1732008.aLNltyhYYo@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.8.0-rc7; KDE/4.9.5; x86_64; ; ) In-Reply-To: <511D0420.8080608@gmail.com> References: <1360170133-5066-1-git-send-email-dirk.brandewie@gmail.com> <1540905.Sh9giL2bZe@vostro.rjw.lan> <511D0420.8080608@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, February 14, 2013 07:34:56 AM Dirk Brandewie wrote: > On 02/14/2013 04:21 AM, Rafael J. Wysocki wrote: > > On Thursday, February 14, 2013 09:38:21 AM Viresh Kumar wrote: > >> On Wed, Feb 13, 2013 at 10:08 PM, Dirk Brandewie > >> wrote: > >>> For the case where both are built-in the load order works my driver uses > >>> device_initcall() and acpi_cpufreq uses late_initcall(). > >>> > >>> For the case where both are a module (which I was sure I tested) you are > >>> right > >>> I will have to do something. > >>> > >>> For now I propose to make my driver built-in only while I sort out the right > >>> solution for the module build. Does this seem reasonable to everyone? > >> > >> Of-course i am missing something here. Why would anybody want to insert > >> acpi-cpufreq module when the system supports the pstate driver. > >> > >> In case they are mutually exclusive, then we can have something like > >> depends on !ACPI-DRIVER in the kconfig option of pstate driver. > > > > Yes. Or the other way around (i.e. make acpi_cpufreq depend on > > !X86_INTEL_PSTATE). > > > > The issue is that acpi-cpufreq still needs to be available for Intel processors > before SandyBridge and for other x86 compatible processors we can't make > intel_pstate and acpi-cpufreq mutually exclusive. Right, I forgot about that and recalled it just a minute after sending that message. > Having intel_pstate built-in solves the issue without the need to patch > acpi-cpufreq. I believe that most distros build the scaling drivers in > so the distro/user will make the explicit decision to use intel_pstate. But then we need to allow the user to choose acpi_cpufreq anyway if it's preferred whatever the reason. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.