Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757355AbZDEHn7 (ORCPT ); Sun, 5 Apr 2009 03:43:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757305AbZDEHnq (ORCPT ); Sun, 5 Apr 2009 03:43:46 -0400 Received: from mail-bw0-f169.google.com ([209.85.218.169]:55002 "EHLO mail-bw0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752861AbZDEHnp (ORCPT ); Sun, 5 Apr 2009 03:43:45 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=pCwqzPXg9vVjpGTW82OHRFbyuFk2WvjRInT3ESF9tfG/MzthQxL6QiIQwrmxshASdf nVP/0VcqvOyeM/dIjSrRi71OUwysIbNbXVGFzyM6s+ZBYT/2EmBkmgTDul5UpV6M41hA fXyZbN7K5oNdl6bfZfmTCTZXA8ERIWxpiCObo= MIME-Version: 1.0 In-Reply-To: <1227567739.6421.44.camel@localhost> References: <1227454026.7262.59.camel@localhost> <492A7632.4040106@compton.nu> <200811241613.25557.trenn@suse.de> <200811241736.53067.trenn@suse.de> <1227567739.6421.44.camel@localhost> Date: Sun, 5 Apr 2009 09:43:40 +0200 Message-ID: <71cd59b00904050043u44d1cd2eu4b8d3aee9027ea17@mail.gmail.com> Subject: Re: [Acpi4asus-user] [PATCH 1/1] cpufreq: eeepc 900 frequency scaling driver From: Corentin Chary To: Cristiano Prisciandaro Cc: Thomas Renninger , Dave Jones , acpi4asus-user@lists.sourceforge.net, linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org, Tom Hughes , linux acpi , Francesco Lattanzio , Matthew Garrett , Grigori Goronzy Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1856 Lines: 44 >> Could it happen that upcoming machines provide this interface (the two ACPI >> functions) and also can do real CPU frequency/volt switching, e.g. via >> acpi-cpufreq? > > Probably this interface is a solution specific to machines based on the > celeron M: I don't even know if other 'old' models provide the same > interface. Hi, We I just received another patch for that (adding a cpufv file in sysfs) and I don't really know what to do. As Grigori Goronzy said, using cpufreq in not a good idea: > 1) dynamic governors like "ondemand" or "conservative" are not suitable > for SHE. It's possible to avoid usage of these by specifying a long > (e.g. UINT_MAX) transition latency. However, the fallback governor is > "performance" which isn't a good idea either, because it'll use the > overclock setting always. For SHE, the default should be the "normal", > non-overclocked frequency. > > 2) The SHE ACPI interface doesn't expose the clock frequencies. I'm > using 750 / 1000 / 1500 KHz at the moment, but that's hacky. cpufreq > does not support performance points with names, such as "powersave", > "normal", "performance", etc. > > 3) It looks like it is impossible to use more than one cpufreq driver > per CPU. This effectively means you can either use the regular ACPI > frequency scaling, which switches between multipliers, or SHE. That's > unacceptable. SHE is not intended to replace the regular frequency > scaling, but to complement it. But adding another specific file for eeepc seems ugly too. Does someone have a great idea to solve that ? Thanks -- Corentin Chary http://xf.iksaif.net -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/