From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755347AbXLGQ3Z (ORCPT ); Fri, 7 Dec 2007 11:29:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752937AbXLGQ3R (ORCPT ); Fri, 7 Dec 2007 11:29:17 -0500 Received: from smtpq1.groni1.gr.home.nl ([213.51.130.200]:36580 "EHLO smtpq1.groni1.gr.home.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752990AbXLGQ3Q (ORCPT ); Fri, 7 Dec 2007 11:29:16 -0500 Message-ID: <4759749E.5070401@keyaccess.nl> Date: Fri, 07 Dec 2007 17:28:14 +0100 From: Rene Herman User-Agent: Thunderbird 2.0.0.9 (X11/20071031) MIME-Version: 1.0 To: "David P. Reed" CC: Andi Kleen , linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" Subject: Re: RFC: outb 0x80 in inb_p, outb_p harmful on some modern AMD64 with MCP51 laptops References: <475879CD.9080006@reed.com> <47595DB2.5080302@reed.com> <20071207145430.GA5992@one.firstfloor.org> <47596A2E.4060602@keyaccess.nl> In-Reply-To: <47596A2E.4060602@keyaccess.nl> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -1.0 (-) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07-12-07 16:43, Rene Herman wrote: > On 07-12-07 15:54, Andi Kleen wrote: > >>> My machine in question, for example, needs no waiting within >>> CMOS_READs at all. And I doubt any other chip/device needs waiting >>> that isn't >> >> I don't know about CMOS, but there were definitely some not too ancient >> systems (let's say not more than 10 years) who required IO delays in the >> floppy driver and the 8253/8259. But on those the jumps are already >> far too fast. > > Also see Alan's replies in the thread I posted a link to: > > http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-09/5700.html > > Also 8254 (PIT) at least it seems. By the way, David, it would be interesting if you could test 0xed. If your problem is some piece of hardware getting upset at LPC bus aborts it's not going to matter and we'd know an outb delay is just not an option on your system at least. You said you could quickly reproduce the problem with port 0x80? Rene.