Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932660AbWJFXG5 (ORCPT ); Fri, 6 Oct 2006 19:06:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932663AbWJFXG5 (ORCPT ); Fri, 6 Oct 2006 19:06:57 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:10415 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S932660AbWJFXGz (ORCPT ); Fri, 6 Oct 2006 19:06:55 -0400 Message-ID: <4526E175.9090608@garzik.org> Date: Fri, 06 Oct 2006 19:06:29 -0400 From: Jeff Garzik User-Agent: Thunderbird 1.5.0.7 (X11/20060913) MIME-Version: 1.0 To: "Duran, Leo" CC: "Rafael J. Wysocki" , Linus Torvalds , Arjan van de Ven , Andi Kleen , discuss@x86-64.org, linux-kernel@vger.kernel.org Subject: Re: [discuss] Re: Please pull x86-64 bug fixes References: <1449F58C868D8D4E9C72945771150BDF46F8FD@SAUSEXMB1.amd.com> In-Reply-To: <1449F58C868D8D4E9C72945771150BDF46F8FD@SAUSEXMB1.amd.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.3 (----) X-Spam-Report: SpamAssassin version 3.1.3 on srv5.dvmed.net summary: Content analysis details: (-4.3 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1303 Lines: 29 Duran, Leo wrote: > OK, lets' take K8 processor performance states (p-states) as an example: > BIOS, which should know 'best' about a given platform, needs to > communicate to the OS what 'voltage' (VID code) is correct for given > 'frequency' (FID), > and it can do that via ACPI processor tables (_PSS). Otherwise, OS code > is left with having to manage a HUGE amount 'specifics' (processor > models), and endless driver revisions to account for new parts. > > So, one can argue that there's merit on having ACPI, it's just a shame > when BIOS doesn't get it right! (thus the justification for lack of > 'trust'... the same can probably be said about other BIOS issues, not > just ACPI) That's pretty much it in a nutshell... Since most BIOS are largely tested and qualified only on That Other OS, Linux often gets the short end of the stick. We have a long history of running into BIOS bugs, and having to work around them. We've learned the hard way that programming the "bare metal" is often the only reliable way to get things done. Jeff - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/