From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dominik Brodowski Subject: Re: Quick, Quick, Slooow Date: Tue, 5 Nov 2002 09:43:34 +0100 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <20021105094334.C1465@brodo.de> References: <20021105001358.A54213@azure.melloworld.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20021105001358.A54213-bxPqUFq66fhTnqHRgSL67VaTQe2KTcn/@public.gmane.org>; from alien-acpirep-xE0Zs7GtCLTd8Zgiw/MPxQ@public.gmane.org on Tue, Nov 05, 2002 at 12:13:59AM +0000 Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: Al Cutter Cc: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org Hi Al, On Tue, Nov 05, 2002 at 12:13:59AM +0000, Al Cutter wrote: > I've just started playing around with this acpi business, but the > processor performance (echo 1 > /proc/acpi/.../performance) didn't seem > to work on my Sony SRX41P, it'd timeout in > acpi_processor_set_performance() ("Transition failed"). > > The cpufreq interface seems to work fine however, so I made a little > patch against acpi-20021101 on 2.5.45 which makes : > * acpi_processor_set_performance() call cpufreq to change the > clock speed, and > * acpi_processor_write_performance() call ..._set_performance() > > Don't know if this makes sense, or it's just a kludge that gets around > my particular problem, but it seems to work quite well with > autospeedstep (http://gpsdrive.kraftvoll.at/speedstep.shtml). Actually, this would be the wrong way 'round: There are several "techniques" to switch the performance states / the CPU freuqency. One is ACPI, others are "legacy" interfaces for Intel SpeedStep, AMD PowerNow, Cyrix Longhaul, Transmeta Crusoe, ... cpufreq offers an unified interface for all these drivers (and a bit more...) - and so you shouldn't even recognize from reading this interface, /proc/cpufreq, what cpufreq driver (ACPI, SpeedStep, etc.) is used. Your patch would actually remove the ACPI cpufreq driver. Additionally, you shouldn't try to use the ACPI generic interface to access a general CPUfreq driver; but use /proc/cpufreq [or /proc/sys/cpu/0/] directly. Dominik ------------------------------------------------------- This sf.net email is sponsored by: See the NEW Palm Tungsten T handheld. Power & Color in a compact size! http://ads.sourceforge.net/cgi-bin/redirect.pl?palm0001en