From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759815AbYD3Ov0 (ORCPT ); Wed, 30 Apr 2008 10:51:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758005AbYD3OvO (ORCPT ); Wed, 30 Apr 2008 10:51:14 -0400 Received: from out4.smtp.messagingengine.com ([66.111.4.28]:34584 "EHLO out4.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756765AbYD3OvN (ORCPT ); Wed, 30 Apr 2008 10:51:13 -0400 X-Sasl-enc: WPbemviR1HEqBqNZHVDqBS0ZkwR40A8jjkCHx8KBMN/e 1209567072 Date: Wed, 30 Apr 2008 11:51:10 -0300 From: Henrique de Moraes Holschuh To: Jean Delvare Cc: Kasper Sandberg , Rudolf Marek , Maxim Levitsky , trenn@suse.de, Len Brown , Matthew , linux-acpi@vger.kernel.org, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, "Zhang, Rui" Subject: Re: Linux 2.6.25 (coretemp reads high temperatures) Message-ID: <20080430145110.GC3543@khazad-dum.debian.net> References: <200804182151.49021.lenb@kernel.org> <200804231143.10875.maximlevitsky@gmail.com> <1209406784.11608.15.camel@localhost> <1209474423.1784.837.camel@queen.suse.de> <20080429170824.09540206@hyperion.delvare> <48179DB4.8040701@assembler.cz> <1209514274.27499.12.camel@localhost> <20080430082005.4b76186f@hyperion.delvare> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20080430082005.4b76186f@hyperion.delvare> X-GPG-Fingerprint: 1024D/1CDB0FE3 5422 5C61 F6B7 06FB 7E04 3738 EE25 DE3F 1CDB 0FE3 User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 30 Apr 2008, Jean Delvare wrote: > On Wed, 30 Apr 2008 02:11:14 +0200, Kasper Sandberg wrote: > > On Wed, 2008-04-30 at 00:14 +0200, Rudolf Marek wrote: > > > Well again, I tried hard at Intel and I really could not get any info on some > > > calibration bit. The temperature is non-physical on arbitrary scale. I changed > > > that so for some people it jumped to 100C, for some it remained. > > > > So, im confused.. The reason for this is that the internal sensor is > > operating on some sort of weird scale, and thus when you interpolate it > > into "your" scale, it doesent quite come out in the actual degrees > > celcius the cpu temperature really is? > > It's really only an offset, rather than scaling. The temperature > reported by the Core and Core2 CPUs is a relative temperature. It tells > how far you are from the maximum temperature the CPU can survive. The > value is expressed in (relative) degrees C. Ah, please ignore my email about ITUs (Intel thermal units), then. The above means 1ITU=1°C, but their zeros are at different places. > Rudolf did his best to find out the (absolute) temperature each CPU > model can survive (known as TJmax) so that the coretemp driver can > provide an absolute temperature to user-space, as all other hardware > monitoring drivers do. Our hope was to limit the confusion, but it > seems we failed ;) Maybe it would be better if the driver was reporting > the relative temperature value directly when we don't know the TJmax > value for sure - but then all user-space tools would need to learn how > to deal with this. Actually, just libsensors would, and the local admin can adjust it at will using the config file. Nobody in userspace should be reading hwmon sysfs directly without the use of libsensors. If they are, it is their bug, and it is unsupported AFAIK. -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh