From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753466AbXLISGR (ORCPT ); Sun, 9 Dec 2007 13:06:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751335AbXLISFh (ORCPT ); Sun, 9 Dec 2007 13:05:37 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:1695 "EHLO spitz.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750940AbXLISFf (ORCPT ); Sun, 9 Dec 2007 13:05:35 -0500 Date: Sun, 9 Dec 2007 13:22:58 +0000 From: Pavel Machek To: "David P. Reed" Cc: Alan Cox , 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 Message-ID: <20071209132258.GG4381@ucw.cz> References: <475879CD.9080006@reed.com> <20071207160439.71b7f46a@the-village.bc.nu> <475AEF8E.5040906@reed.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <475AEF8E.5040906@reed.com> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat 2007-12-08 14:25:02, David P. Reed wrote: > > > Alan Cox wrote: > > > >0x80 should be fine for anything PC compatible anyway, > >its specifically > >reserved as a debug port and supported for *exactly* > >that purpose by > >many chipsets. > > > > > Disagree. The definitions of PC compatible are quite > problematic. I have the advantage over some of you > young guys, in that I actually wrote code on one of the > first 5 breadboard IBM PCs on the planet at Software > Arts, Inc. and I was directly involved in hardware spec > projects with the original IBM and Compaq engineers. No > one actually defined the port numbered 80h as a > "standard" for anything. You won't find it documented > in any early manual for an IBM machine. > > The ISA bus supported unterminated transactions safely. > That allowed some clever folks to design BIOS diagnostic > tools that optionally plugged into the bus. > > In any case, my machine does not have an ISA bus. Why > should it? It's a laptop! There are mini-pci based cards with port 0x80 displays for notebooks. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html