From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267264AbUHWAcs (ORCPT ); Sun, 22 Aug 2004 20:32:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267327AbUHWAcs (ORCPT ); Sun, 22 Aug 2004 20:32:48 -0400 Received: from gort.metaparadigm.com ([203.117.131.12]:14052 "EHLO gort.metaparadigm.com") by vger.kernel.org with ESMTP id S267264AbUHWAcp (ORCPT ); Sun, 22 Aug 2004 20:32:45 -0400 Message-ID: <41293B41.5040800@metaparadigm.com> Date: Mon, 23 Aug 2004 08:33:05 +0800 From: Michael Clark Organization: Metaparadigm Pte Ltd User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.1) Gecko/20040802 Debian/1.7.1-5 X-Accept-Language: en MIME-Version: 1.0 To: "Clark, Michael" Cc: Pavel Machek , jeremy@goop.org, davej@codemonkey.org.uk, Linux Kernel Subject: Re: [PATCH] - Initial dothan speedstep support References: <41131120.5060202@metaparadigm.com> <20040818135314.GJ467@openzaurus.ucw.cz> <56689.210.86.92.219.1093159902.squirrel@mail.metaparadigm.com> In-Reply-To: <56689.210.86.92.219.1093159902.squirrel@mail.metaparadigm.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 08/22/04 15:31, Clark, Michael wrote: >>Hi! >> >> >>>So here's a patch on top of the above patch that adds all of the >>>dothan frequency/voltages for processors 715, 725, 735, 745, 755 >>> >>>Tested and working as it should so far with a 745. The stepping in the >>>model table for the others may need to be tweaked. >>> >>>The Dothan processor datasheet 30218903.pdf defines 4 voltages for >>>each frequency (VID#A through VID#D) whereas Banias only suggests a >>>typical voltage and no min or max for each freq so i've used the OP >>>macro to allow definition of all voltages (A through D) but the macro >>>currently just uses VID#C at compile time (the second lowest voltage >>>profile). >> >>I thought that whether to use VID#A, B, C or D depends on >>your concrete chip? Not all chips are certified to run on VID#C... > > > Yes, I believe this is the case. When I read the processor spec > document it did not mention this but since then i found this out. I've > since changed the patch to use the VID#A voltages which is more > conservative (assuming that all of them will run at the higher voltage > okay which according to the upper voltage rating of 1.6 volts might be On re-looking at the spec and the voltage tolerance tables in particular I realize my approach is not valid. A VID#B can be driven at VID#A voltages but there is no voltage in common for some frequencies between all VID# variants. > okay). It would of course be preferrable to work out the the type > VID#A,B,C,D via software - not sure if this is possible. Perhaps the VID# variant can be found via MSRs - if not the static tables will not be workable and the ACPI approach will have to be the sole method. ~mc