From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262411AbVGGAXG (ORCPT ); Wed, 6 Jul 2005 20:23:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262212AbVGFUAn (ORCPT ); Wed, 6 Jul 2005 16:00:43 -0400 Received: from main.gmane.org ([80.91.229.2]:46518 "EHLO ciao.gmane.org") by vger.kernel.org with ESMTP id S262223AbVGFQum (ORCPT ); Wed, 6 Jul 2005 12:50:42 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Pedro Ramalhais Subject: Re: speedstep-centrino on dothan Date: Wed, 06 Jul 2005 17:30:14 +0100 Message-ID: <42CC0716.9030108@serrado.net> References: <20050706112202.33d63d4d@horst.morte.male> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@sea.gmane.org X-Gmane-NNTP-Posting-Host: gandalf.uninova.pt User-Agent: Debian Thunderbird 1.0.2 (X11/20050602) X-Accept-Language: en-us, en In-Reply-To: <20050706112202.33d63d4d@horst.morte.male> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org st3@riseup.net wrote: > Currently, the speedstep-centrino support has built-in frequency/voltage > pairs only for Banias CPUs. For Dothan CPUs, these tables are read from > BIOS ACPI. > > But ACPI encoding may not be available or not reliable, so why shouldn't we > provide built-in tables for Dothan CPUs, too? Intel has released this > datasheet: > > http://www.intel.com/design/mobile/datashts/302189.htm > > with frequency/voltage pairs for every version of Dothan CPUs. > > Moreover, I checked on Pentium M 725 and Pentium M 715 that the lowest > frequency at which the CPU can be set safely is not the 600MHz given in > datasheets, but 400MHz instead, with VID#A, VID#B, VID#C and VID#D (see > datasheet for more details) set to 0.908V. > > I can provide a patch, let me know. > > > -- > ciao > st3 > I looked into it 2 weeks ago, and i couldn't find a complete voltage table for the Dothan C1 stepping (which my laptop has). I only found a table with (IIRC) the max and min voltages for the max and min frequencies. I also didn't understand the meaning of the different VID#{A,B,C,D,E} values. Are these voltages related to the quality of the power supply, or the quality of the processor? How do we know which one to choose? Regards, -- Pedro Ramalhais