From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261318AbVALJui (ORCPT ); Wed, 12 Jan 2005 04:50:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261322AbVALJui (ORCPT ); Wed, 12 Jan 2005 04:50:38 -0500 Received: from zone4.gcu-squad.org ([213.91.10.50]:40394 "EHLO zone4.gcu-squad.org") by vger.kernel.org with ESMTP id S261318AbVALJu1 convert rfc822-to-8bit (ORCPT ); Wed, 12 Jan 2005 04:50:27 -0500 Date: Wed, 12 Jan 2005 10:44:41 +0100 (CET) To: pioppo@ferrara.linux.it Subject: Re: 2.6.10-mm2: it87 sensor driver stops CPU fan X-IlohaMail-Blah: khali@localhost X-IlohaMail-Method: mail() [mem] X-IlohaMail-Dummy: moo X-Mailer: IlohaMail/0.8.13 (On: webmail.gcu.info) Message-ID: In-Reply-To: <200501112205.02322.pioppo@ferrara.linux.it> From: "Jean Delvare" Bounce-To: "Jean Delvare" CC: "LM Sensors" , "Jonas Munsin" , djg@pdp8.net, "Greg KH" , "LKML" MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi Simone, > > 2* I would then add a check to the it87 driver, which completely disables > > the fan speed control interface if the initial configuration looks weird > > (all fans supposedly stopped and polarity set to "active low"). This > > should protect users of the driver who have a faulty BIOS. > > If the driver can perform a similar guess, couldn't it also activate a > reverse polarity mode as well? I think all systems boot with with > full-speed fan, so any value you found at loading time should be the > full-speed one, shouln't it? I'm thinking about this. However, there are a couple things to keep in mind: 1* The driver is not necessarily loaded at boot time. For example, one might unload and reload the module. In this case, fans might have been configured for less-then-full speed, and we have to handle this case properly. 2* This is just a guess. If we are wrong, the user is in trouble. You know what I mean ;) For this reason, it sounds better if the user has to activate a module parameter by his/herself, because it means he/she is aware that bad things might happen. 3* This is really a workaround for buggy BIOS. It would be better is BIOSes were fixed instead. It is time that manufacturer improve the quality of the BIOSes for the hardware monitoring parts. I have seen brokenesses ain too many BIOSes to keep count of them. Silently working around the bugs in the Linux driver is not going to help that. That said, if no problems are reported after some time, we might consider to apply the workaround by default. One thing at a time though. > BTW: > I'm writing a report to giga-byte. OK. Let us know how it goes. Feel free to direct them to me if you think it can be of any help. -- Jean Delvare