From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nate Lawson Subject: RE: can't switch CPU frequency while running on batterypower Date: Tue, 6 Jan 2004 10:42:02 -0800 (PST) Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <20040106103944.Q26693@root.org> References: <3ACA40606221794F80A5670F0AF15F8401720C76@PDSMSX403.ccr.corp.intel.com> <32908.192.168.36.2.1073412456.squirrel@defiant.homedns.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <32908.192.168.36.2.1073412456.squirrel-4AGA6j5e2AhmdDG0eupGX0B+6BGkLq7r@public.gmane.org> Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Defiant Cc: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org On Tue, 6 Jan 2004, Defiant wrote: > >> CONFIG_X86_ACPI_CPUFREQ=y > >> CONFIG_X86_ACPI_CPUFREQ_PROC_INTF=y > > > > Please try patch filed at > > http://bugzilla.kernel.org/show_bug.cgi?id=1489 > > Tried the patch, but it didn't solved the Problem. > > Well at least I found out some more Info about. > My full speed is 1600, low speed is 1200Mhz: > > When running on AC Adapter, I can switch the speed as often as I want. > So If I set it to 1200 and then disconnect the AC, I can also switch > between both speeds under battery power. Now If it is 1200 and I connect > the AC I can not set it back to 1600. > Well like I said in my preceding post it is the same: Running with AC, > speed set to 1600, disconnecting the AC, I can not set the speed down to > 1200. This is most likely a problem with re-evaluation of _PSS after it has been changed. I don't remember if Linux uses the notify on the processor object to re-evaluate _PSS. If Linux does this correctly, it may be that the underlying firmware has a bug and you should use a more specific cpufreq driver (i.e. SpeedStep or whatever). Some systems have a problem where they don't properly export firmware information to the ACPI performance states interface. -Nate ------------------------------------------------------- This SF.net email is sponsored by: IBM Linux Tutorials. Become an expert in LINUX or just sharpen your skills. Sign up for IBM's Free Linux Tutorials. Learn everything from the bash shell to sys admin. Click now! http://ads.osdn.com/?ad_id=1278&alloc_id=3371&op=click