Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754849AbXJ3WfQ (ORCPT ); Tue, 30 Oct 2007 18:35:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752233AbXJ3WfC (ORCPT ); Tue, 30 Oct 2007 18:35:02 -0400 Received: from outbound-mail-15.bluehost.com ([69.89.18.115]:46041 "HELO outbound-mail-15.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751574AbXJ3WfA (ORCPT ); Tue, 30 Oct 2007 18:35:00 -0400 From: Jesse Barnes To: Linus Torvalds Subject: Re: pci-disable-decode-of-io-memory-during-bar-sizing.patch Date: Tue, 30 Oct 2007 15:31:57 -0700 User-Agent: KMail/1.9.7 Cc: Arjan van de Ven , Robert Hancock , Greg KH , akpm@linux-foundation.org, ak@suse.de, rajesh.shah@intel.com, linux-kernel References: <200708151919.l7FJJfUE010966@imap1.linux-foundation.org> <200710301504.36972.jbarnes@virtuousgeek.org> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200710301531.58957.jbarnes@virtuousgeek.org> X-Identified-User: {642:box128.bluehost.com:virtuous:virtuousgeek.org} {sentby:smtp auth 76.103.130.182 authed with jbarnes@virtuousgeek.org} X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - box128.bluehost.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [642 12] / [47 12] X-AntiAbuse: Sender Address Domain - virtuousgeek.org Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1888 Lines: 45 On Tuesday, October 30, 2007 3:22 pm Linus Torvalds wrote: > On Tue, 30 Oct 2007, Jesse Barnes wrote: > > The per-device flag is fine with me, but I should make something > > clear: > > > > MMCONFIG IS NOT BROKEN! > > Trust me, it is. > > The particular problem _you_ had with it is only a small small part > of the bugs we have had. > > > What's broken is our PCI probing with certain address space layouts > > that include MMCONFIG space. > > No. You really don't see the big picture. There's been tons of > problems with MMCONFIG. Like the fact that other devices have their > IO regions registered on top of it, because the MMCONFIG thing was > done as a hidden resource. Or the fact that the area claimed was too > small. Or too large. Or not listed at all. Yeah, that's definitely a problem, and would be a firmware bug. There's no doubt that firmwares have had trouble with this in the past, but given that Vista now relies on this stuff working, it's a lot more likely to be reliable in current and future systems. > The whole thing is a total disaster. I told Intel engineers literally > *years* ago to not do that idiotic "hidden IO resources that are > described by firmware that then inevitably gets things wrong", and > yet what happens? Every single time. I don't disagree there. I'm just saying the actual mechanism is fine (as illustrated by the numerous non-PC ports of Linux), and this particular problem, at least, isn't really specific to how MMCONFIG is described or configured by the firmware and OS, it's simply a Linux problem. But like I said, the per-device flag Arjan suggested is fine with me... Jesse - 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/