From mboxrd@z Thu Jan 1 00:00:00 1970 From: Karol Kozimor Subject: Re: Kernel 2.4.23 passive cooling Date: Tue, 2 Dec 2003 13:26:45 +0100 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <20031202122644.GA6024@hell.org.pl> References: <1070301739.1353.6.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-2 Return-path: Content-Disposition: inline In-Reply-To: <1070301739.1353.6.camel-bi+AKbBUZKZeoWH0uzbU5w@public.gmane.org> Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Nils Faerber Cc: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org Thus wrote Nils Faerber: > Hi! > Passive cooling still seems a little strange, at least to me on my Asus > L3800C notebook. [...] > - passive cooling works until it reaches the first hot state. After > that the fan(s) power up for a very short time and the CPU performance > is set to maximum (!) again. The performance setting can afterwards not > be reset to low performance anymore; it will be reset to high > automatically! Use the limit interface instead of directly manipulating the CPU0/performance -- this *may* help. > Is there any chance that this will be fixed? > Or is this a BIOS bug? I'm not sure, but I haven't really had enough time to trace the appropriate AML codepath -- I can obviously also experience the problem. Oddly enough, the first time I booted ACPI 20031002 (just in order to see if improved index field access will fix the passive cooling problem), the processor went up to about 83 C without the fan kicking in (I can't remember if throttling was on at that time, but I guess it should have been). I then switched to active (the fans started spinning like mad), and back to passive, which apparently didn't stop the fans. What I suspect is that there are some semi-obscure things going on in the AML and it would take me at least two or three cups of coffee to trace it. I'll see what I can do. Note: most of the thermal management is done by the AML and not by the OS, as th OS doesn't know about most tresholds. Best regards, -- Karol 'sziwan' Kozimor sziwan-DETuoxkZsSqrDJvtcaxF/A@public.gmane.org ------------------------------------------------------- This SF.net email is sponsored by: SF.net Giveback Program. Does SourceForge.net help you be more productive? Does it help you create better code? SHARE THE LOVE, and help us help YOU! Click Here: http://sourceforge.net/donate/