Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761944AbYAKURa (ORCPT ); Fri, 11 Jan 2008 15:17:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762482AbYAKURV (ORCPT ); Fri, 11 Jan 2008 15:17:21 -0500 Received: from palinux.external.hp.com ([192.25.206.14]:48992 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762419AbYAKURS (ORCPT ); Fri, 11 Jan 2008 15:17:18 -0500 Date: Fri, 11 Jan 2008 13:17:16 -0700 From: Matthew Wilcox To: Linus Torvalds Cc: Greg KH , Arjan van de Ven , Greg KH , linux-kernel@vger.kernel.org, Jeff Garzik , linux-pci@atrey.karlin.mff.cuni.cz, Benjamin Herrenschmidt , Martin Mares Subject: Re: [Patch v2] Make PCI extended config space (MMCONFIG) a driver opt-in Message-ID: <20080111201716.GO18741@parisc-linux.org> References: <20071225032605.29147200@laptopd505.fenrus.org> <20080111190229.GB10112@kroah.com> <20080111192820.GM18741@parisc-linux.org> <20080111114002.3e59d1ad@laptopd505.fenrus.org> <20080111194524.GA17170@suse.de> <20080111194931.GN18741@parisc-linux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1382 Lines: 33 On Fri, Jan 11, 2008 at 11:58:23AM -0800, Linus Torvalds wrote: > On Fri, 11 Jan 2008, Matthew Wilcox wrote: > > > > So your argument is that MMCONFIG sucks, therefore Linux has to have a > > horrible interface to extended PCI config space? > > What's *your* point? > > MMCONFIG is known broken. If we ever start enabling it more (ie start > using it even if it's not reserved in the e820 tables), all that known > breakage will come and bite us in the *ss. Ivan's patch doesn't start enabling MMCONFIG in more places than we currently do. It makes us use conf1 accesses for all accesses below 256 bytes. That fixes all known problems to date. > We need to have some armor-plated underwear to protect against that > ass-biting, and that's what Arjan's patch is. > > Tell me what *other* armor plating you could have that actually works? The armour plating that already exists -- pci=nommconf. -- Intel are signing my paycheques ... these opinions are still mine "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- 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/