Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757853AbXLLQTs (ORCPT ); Wed, 12 Dec 2007 11:19:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752401AbXLLQTk (ORCPT ); Wed, 12 Dec 2007 11:19:40 -0500 Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:33904 "EHLO the-village.bc.nu" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751835AbXLLQTj (ORCPT ); Wed, 12 Dec 2007 11:19:39 -0500 Date: Wed, 12 Dec 2007 16:12:45 +0000 From: Alan Cox Cc: "Rene Herman" , "Paul Rolland" , "H. Peter Anvin" , "Krzysztof Halasa" , "Pavel Machek" , "Andi Kleen" , , "Thomas Gleixner" , "Ingo Molnar" , Subject: Re: RFC: outb 0x80 in inb_p, outb_p harmful on some modern AMD64 with MCP51 laptops Message-ID: <20071212161245.3f388229@the-village.bc.nu> In-Reply-To: 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> <20071211084059.3d03e11d@tux.DEF.witbe.net> <475E5D4B.8020101@keyaccess.nl> <475E7DC2.4060509@davidnewall.com> <475E8D91.20201@keyaccess.nl> <20071211143224.15900995@tux.DEF.witbe.net> <475E9B9B.2050709@keyaccess.nl> <475EACB8.7080608@keyaccess.nl> <20071211163706.2dc82275@tux.DEF.witbe.net> <475EB263.2050405@keyaccess.nl> <475EC1C0.2040000@reed.com> <20071211173231.2b87a81f@the-village.bc.nu> <475EE2CA.6020601@reed.com> <475F23BD.3040903@reed.com> X-Mailer: Claws Mail 2.10.0 (GTK+ 2.10.14; i386-redhat-linux-gnu) Organization: Red Hat UK Cyf., Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, Y Deyrnas Gyfunol. Cofrestrwyd yng Nghymru a Lloegr o'r rhif cofrestru 3798903 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 769 Lines: 25 There is another reason we can't just do a dumb changeover - two actually #1: Some drivers are using inb_p/outb_p in PCI cases which are going to cause PCI posting changes. Most are probably just wrong in the first place but they need hand checking #2: We've got SMP cases that only 'work' because the odds of splitting the outb and the following port 0x80 cycle, which locks the bus, are tiny. That is we've got CPU1 CPU2 main path irq path outb outb inb 0x80 inb 0x80 races in one or two spots. -- 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/