From mboxrd@z Thu Jan 1 00:00:00 1970 From: Len Brown Subject: RE: fan always on: ACPI on IBM ThinkPad R51 Date: 01 Sep 2004 13:08:17 -0400 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <1094058497.2053.8.camel@d845pe> References: <20040901100349.4B7A28254@smtp.causaencantada.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20040901100349.4B7A28254-1pm5EDj67X3XwkDZ9D75p87Q1tIk23pb@public.gmane.org> Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: susinho-32FzPoaopq1AfugRpC6u6w@public.gmane.org Cc: ACPI Developers , linux-thinkpad-l7BEYHA5S10i5T99jlK1Sh2eb7JE58TQ@public.gmane.org, Zhenyu Z Wang List-Id: linux-acpi@vger.kernel.org On Wed, 2004-09-01 at 06:05, susinho-32FzPoaopq1AfugRpC6u6w@public.gmane.org wrote: > Thank you for this info. > > I opened the laptop and found a three wire connector to the fan, wich > usually means speed control by BIOS. Disconnecting the fan, a "Fan > failure" appears and booting process stops. So I supose the fan speed > and switches are controlled by non-ACPI parts of the BIOS. > > In this case, adding a fan device in the dsdt could make ACPI handle the > fan? Is this possible, or the only way is to modify the BIOS? Such an ACPI device would need methods, and those methods would read and write platform-specific hardware registers. This is the job of the BIOS writer at IBM. But apparently on this model IBM has a non-ACPI means to handle the fans, probably an embedded controller. -Len > O 31/8/2004, "Wang, Zhenyu Z" escribiu: > > >There is no fan device in your dsdt. That means ACPI fan driver couldn't > >handle it. > > ------------------------------------------------------- This SF.Net email is sponsored by BEA Weblogic Workshop FREE Java Enterprise J2EE developer tools! Get your free copy of BEA WebLogic Workshop 8.1 today. http://ads.osdn.com/?ad_id=5047&alloc_id=10808&op=click