Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936735AbXLQUKK (ORCPT ); Mon, 17 Dec 2007 15:10:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934816AbXLQToX (ORCPT ); Mon, 17 Dec 2007 14:44:23 -0500 Received: from mho-02-bos.mailhop.org ([63.208.196.179]:50221 "EHLO mho-02-bos.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934675AbXLQToW (ORCPT ); Mon, 17 Dec 2007 14:44:22 -0500 X-Mail-Handler: MailHop Outbound by DynDNS X-Originating-IP: 18.85.9.136 X-Report-Abuse-To: abuse@dyndns.com (see http://www.mailhop.org/outbound/abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX183o7C+MHlf3l7ObqBBGsBn Message-ID: <4766D175.7040807@reed.com> Date: Mon, 17 Dec 2007 14:43:49 -0500 From: "David P. Reed" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.1.5) Gecko/20070727 Fedora/2.0.0.5-2.fc7 Thunderbird/2.0.0.5 Mnenhy/0.7.5.0 MIME-Version: 1.0 To: "H. Peter Anvin" CC: Rene Herman , Ingo Molnar , Paul Rolland , Alan Cox , Pavel Machek , Thomas Gleixner , linux-kernel@vger.kernel.org, Ingo Molnar , rol@witbe.net Subject: Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override. References: <4762C551.5070003@zytor.com> <20071214210652.GB28793@elf.ucw.cz> <4763001A.1070102@zytor.com> <20071214232955.545ab809@the-village.bc.nu> <20071215080831.404cdb32@tux.DEF.witbe.net> <47638C8C.2090604@gmail.com> <476438B4.2020600@zytor.com> <476462BE.3030701@gmail.com> <4764687D.6080609@zytor.com> <476524DB.7020806@gmail.com> <20071216152250.GA21245@elte.hu> <4765D43E.1010800@gmail.com> <4765D95C.4010404@zytor.com> <4765DCB0.8030901@gmail.com> <4765EE7F.80002@zytor.com> <47667366.7010405@gmail.com> <4766AE88.4080904@zytor.com> In-Reply-To: <4766AE88.4080904@zytor.com> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 911 Lines: 21 H. Peter Anvin wrote: > Rene Herman wrote: >> >> I do not know how universal that is, but _reading_ port 0xf0 might in >> fact be sensible then? And should even work on a 386/387 pair? (I >> have a 386/387 in fact, although I'd need to dig it up). >> > > No. Someone might have used 0xf0 as a readonly port for other uses. > As support: port 80 on the reporter's (my) HP dv9000z laptop clearly responds to reads differently than "unused" ports. In particular, an inb takes 1/2 the elapsed time compared to a read to "known" unused port 0xed - 792 tsc ticks for port 80 compared to about 1450 tsc ticks for port 0xed and other unused ports (tsc at 800 MHz). -- 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/