Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754692AbYANV65 (ORCPT ); Mon, 14 Jan 2008 16:58:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750968AbYANV6s (ORCPT ); Mon, 14 Jan 2008 16:58:48 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:60136 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750903AbYANV6r (ORCPT ); Mon, 14 Jan 2008 16:58:47 -0500 Subject: Re: [linux-kernel] Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override. From: David Woodhouse To: "David P. Reed" Cc: Rene Herman , Zachary Amsden , "H. Peter Anvin" , Christer Weinigel , Ondrej Zary , Bodo Eggert <7eggert@gmx.de>, Ingo Molnar , Alan Cox , Paul Rolland , Pavel Machek , Thomas Gleixner , linux-kernel@vger.kernel.org, Ingo Molnar , rol In-Reply-To: <47877ECD.9060408@reed.com> References: <9BdU5-1YW-9@gated-at.bofh.it> <200801081810.58904.linux@rainbow-software.org> <4783B1B2.6070005@reed.com> <200801081838.16241.linux@rainbow-software.org> <4783C4A6.9060402@reed.com> <20080108185120.3ff7ed18@lxorguk.ukuu.org.uk> <4783CBD9.7020709@reed.com> <1199847162.7369.323.camel@bodhitayantram.eng.vmware.com> <47845972.9090803@zytor.com> <1199915614.7369.367.camel@bodhitayantram.eng.vmware.com> <47854916.4080703@reed.com> <1200015388.6192.22.camel@bodhitayantram.eng.vmware.com> <4786DD05.20804@keyaccess.nl> <47877ECD.9060408@reed.com> Content-Type: text/plain Date: Tue, 15 Jan 2008 05:57:27 +0800 Message-Id: <1200347847.2647.97.camel@shinybook.infradead.org> Mime-Version: 1.0 X-Mailer: Evolution 2.12.2 (2.12.2-3.fc8.dwmw2.1) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 725 Lines: 20 On Fri, 2008-01-11 at 09:35 -0500, David P. Reed wrote: > Using any "unused port" for a delay means that the machine check > feature is wasted and utterly unusable. Not entirely unusable. You can recover silently from the machine check if it was one of the known accesses to the 'unused port'. It certainly achieves a delay :) On ppc32 we recover from the machine check if it was any inb/outb -- mostly to work around crappy drivers developed on i386, I believe. -- dwmw2 -- 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/