From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752722AbXLKHrl (ORCPT ); Tue, 11 Dec 2007 02:47:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751976AbXLKHrc (ORCPT ); Tue, 11 Dec 2007 02:47:32 -0500 Received: from smtp.witbe.net ([81.88.96.48]:59795 "EHLO smtp.witbe.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751735AbXLKHrb convert rfc822-to-8bit (ORCPT ); Tue, 11 Dec 2007 02:47:31 -0500 X-Greylist: delayed 317 seconds by postgrey-1.27 at vger.kernel.org; Tue, 11 Dec 2007 02:47:31 EST Date: Tue, 11 Dec 2007 08:40:59 +0100 From: Paul Rolland To: David Newall Cc: "H. Peter Anvin" , Krzysztof Halasa , Rene Herman , Pavel Machek , Andi Kleen , Alan Cox , "David P. Reed" , linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , rol@witbe.net Subject: Re: RFC: outb 0x80 in inb_p, outb_p harmful on some modern AMD64 with MCP51 laptops Message-ID: <20071211084059.3d03e11d@tux.DEF.witbe.net> In-Reply-To: <475DEB23.1000304@davidnewall.com> References: <475879CD.9080006@reed.com> <20071207160439.71b7f46a@the-village.bc.nu> <20071209125458.GB4381@ucw.cz> <20071209165908.GA15910@one.firstfloor.org> <20071209212513.GC24284@elf.ucw.cz> <475CBDD7.5050602@keyaccess.nl> <475DE37F.20706@davidnewall.com> <475DE6F4.80702@zytor.com> <475DEB23.1000304@davidnewall.com> Organization: AS2917.net X-Mailer: Claws Mail 3.1.0 (GTK+ 2.10.14; i686-pc-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Tue, 11 Dec 2007 12:12:59 +1030 David Newall wrote: > H. Peter Anvin wrote: > > David Newall wrote: > > > > I think a single ISA bus transaction is 1 µs, so two of them back to > > back should be 2 µs, not 8 µs... > > Exactly. You think it's 2us, but the documentation doesn't say. The _p > functions are generic inasmuch as they provide an unspecified delay. Well, if the delay is so much unspecified, what about _reading_ port 0x80 ? Will the delay be shorter ? And if so, what about reading port 0x80 and writing the value back ? inb al,0x80 outb 0x80,al I've been wondering since the beginning of this thread if the problem is not just the value we put to port 0x80, not writing to the port... Just my 0.02 Eur... Paul -- Paul Rolland E-Mail : rol(at)witbe.net Witbe.net SA Tel. +33 (0)1 47 67 77 77 Les Collines de l'Arche Fax. +33 (0)1 47 67 77 99 F-92057 Paris La Defense RIPE : PR12-RIPE Please no HTML, I'm not a browser - Pas d'HTML, je ne suis pas un navigateur "Some people dream of success... while others wake up and work hard at it" "I worry about my child and the Internet all the time, even though she's too young to have logged on yet. Here's what I worry about. I worry that 10 or 15 years from now, she will come to me and say 'Daddy, where were you when they took freedom of the press away from the Internet?'" --Mike Godwin, Electronic Frontier Foundation