From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765555AbXLPJlB (ORCPT ); Sun, 16 Dec 2007 04:41:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757603AbXLPJkw (ORCPT ); Sun, 16 Dec 2007 04:40:52 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:39910 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757587AbXLPJkv (ORCPT ); Sun, 16 Dec 2007 04:40:51 -0500 Date: Sun, 16 Dec 2007 10:40:29 +0100 From: Ingo Molnar To: "H. Peter Anvin" Cc: Pavel Machek , "David P. Reed" , Thomas Gleixner , linux-kernel@vger.kernel.org, Ingo Molnar , Rene Herman Subject: Re: [PATCH] x86_64: fix problems due to use of "outb" to port 80 on some AMD64x2 laptops, etc. Message-ID: <20071216094029.GD27280@elte.hu> References: <1184216528.12353.203.camel@chaos> <1184218962.12353.209.camel@chaos> <46964352.7040301@reed.com> <1184253339.12353.223.camel@chaos> <469697C6.50903@reed.com> <1184274754.12353.254.camel@chaos> <4761F193.7090400@reed.com> <20071214131502.GA14359@elte.hu> <20071215230036.GF2434@elf.ucw.cz> <47645D66.4020506@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <47645D66.4020506@zytor.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * H. Peter Anvin wrote: > Pavel Machek wrote: >>> >>> this is also something for v2.6.24 merging. >> >> As much as I like this patch, I do not think it is suitable for >> .24. Too risky, I'd say. >> > > No kidding! We're talking about removing a hack that has been > successful on thousands of pieces of hardware over 15 years because it ^----[*] > breaks ONE machine. [*] "- none of which needs it anymore -" there, fixed it for you ;-) So lets keep this in perspective: this is a hack that only helps on a very low number of systems. (the PIT of one PII era chipset is known to be affected) unfortunately this hack's side-effects are mis-used by an unknown number of drivers to mask PCI posting bugs. We want to figure out those bugs (safely and carefully) and we want to remove this hack from modern machines that dont need it. Doing anything else would be superstition. anyway, we likely wont be doing anything about this in .24. Ingo