From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 15 Sep 2001 14:02:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 15 Sep 2001 14:02:41 -0400 Received: from ns1.uklinux.net ([212.1.130.11]:39177 "EHLO s1.uklinux.net") by vger.kernel.org with ESMTP id ; Sat, 15 Sep 2001 14:02:30 -0400 Envelope-To: linux-kernel@vger.kernel.org Mime-Version: 1.0 Message-Id: In-Reply-To: <01091510441001.00174@c779218-a> In-Reply-To: <01091510441001.00174@c779218-a> Date: Sat, 15 Sep 2001 19:02:37 +0100 To: tegeran@home.com From: Jonathan Morton Subject: Re: Athlon: Try this (was: Re: Athlon bug stomping #2) Cc: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" ; format="flowed" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > > > +static void __init pci_fixup_athlon_bug(struct pci_dev *d) >> > +{ >> > + u8 v; >> > + pci_read_config_byte(d, 0x55, &v); >> > + if(v & 0x80) { >> > + printk(KERN_NOTICE "Stomping on Athlon bug.\n"); >> > + v &= 0x7f; /* clear bit 55.7 */ >> > + pci_write_config_byte(d, 0x55, v); >> > + } >> > +} >> > >> > Well, these are cosmetic changes anyway... >> > What is more important now: >> > 1) Do we have people who still see Athlon bug with the patch? >> > 2) Do Alan read these messages? ;-) >> >> Im watching the discussion with interest. If it proves to be the magic >> bullet I will ask VIA for guidance on the issue > >Not being a developer or guru on the internal software workings of the >hardware here, I have to ask, does this clear up some bug, or does it >disable the optimizations causing the problem? Is this a *fix* or a >band-aid? AFAICT, it's a *fix*. The register in question is "for debug use only, never write anything other than zero in it" but generally shows non-zero when a faulty BIOS is installed. We're zeroing the bit that appears to cause the problem. It's highly unlikely to be an extra optimisation - if it is, it's an unsafe one. -- -------------------------------------------------------------- from: Jonathan "Chromatix" Morton mail: chromi@cyberspace.org (not for attachments) website: http://www.chromatix.uklinux.net/vnc/ geekcode: GCS$/E dpu(!) s:- a20 C+++ UL++ P L+++ E W+ N- o? K? w--- O-- M++$ V? PS PE- Y+ PGP++ t- 5- X- R !tv b++ DI+++ D G e+ h+ r++ y+(*) tagline: The key to knowledge is not to rely on people to teach you it.