From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765964AbXLPXYN (ORCPT ); Sun, 16 Dec 2007 18:24:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760162AbXLPXX4 (ORCPT ); Sun, 16 Dec 2007 18:23:56 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:43745 "EHLO amd.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1759179AbXLPXXz (ORCPT ); Sun, 16 Dec 2007 18:23:55 -0500 Date: Mon, 17 Dec 2007 00:23:53 +0100 From: Pavel Machek To: "David P. Reed" Cc: "H. Peter Anvin" , Ingo Molnar , 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: <20071216232353.GC5692@elf.ucw.cz> References: <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> <20071216094029.GD27280@elte.hu> <47659BF3.4040100@zytor.com> <4765AF78.60307@reed.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4765AF78.60307@reed.com> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! > The process of safely making delicate changes here is beyond my > responsibility as just a user - believe me, I'm not suggesting that a risky > fix be put in .24. I can patch my own kernels, and I can even share an > unofficial patch with others for now, or suggest that Fedora and Ubuntu add > it to their downstream. > > May I make a small suggestion, though. If the decision is a DMI-keyed > switch from out-80 to udelay(2) gets put in, perhaps there should also be > a way for people to test their own configuration for the underlying problem > made available as a script. Though it is a "hack", all you need to freeze > a problem system is to run a loop doing about 1000 "cat /dev/nvram > > /dev/null" commands. If that leads to a freeze, one might ask to have the > motherboard added to the DMI-key list. Can you freeze it by catting /dev/rtc, too? That may be significant, because that is readable for group audio (at least on some systems)... which would smell like "small security hole" to me. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html