From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755152AbYAMEr6 (ORCPT ); Sat, 12 Jan 2008 23:47:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753465AbYAMErv (ORCPT ); Sat, 12 Jan 2008 23:47:51 -0500 Received: from palinux.external.hp.com ([192.25.206.14]:38716 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753461AbYAMEru (ORCPT ); Sat, 12 Jan 2008 23:47:50 -0500 Date: Sat, 12 Jan 2008 21:47:48 -0700 From: Matthew Wilcox To: Arjan van de Ven Cc: tcamuso@redhat.com, Ivan Kokshaysky , Greg KH , Linus Torvalds , Greg KH , linux-kernel@vger.kernel.org, Jeff Garzik , linux-pci@atrey.karlin.mff.cuni.cz, Benjamin Herrenschmidt , Martin Mares , Loic Prylli , Prarit Bhargava , "Chumbalkar, Nagananda" , "Schoeller, Patrick (Linux - Houston, TX)" , Bhavana Nagendra Subject: Re: [Patch v2] Make PCI extended config space (MMCONFIG) a driver opt-in Message-ID: <20080113044748.GY18741@parisc-linux.org> References: <20080111235856.GA16079@jurassic.park.msu.ru> <20080112002638.GA18710@kroah.com> <20080112144030.GA19279@jurassic.park.msu.ru> <20080112094557.71f5382a@laptopd505.fenrus.org> <20080112214911.GA20102@jurassic.park.msu.ru> <20080112150120.05f93768@laptopd505.fenrus.org> <47895767.3090503@redhat.com> <20080112164006.6f6f7bc2@laptopd505.fenrus.org> <47896B3B.2000108@redhat.com> <20080112204248.29abb1dd@laptopd505.fenrus.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080112204248.29abb1dd@laptopd505.fenrus.org> 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 On Sat, Jan 12, 2008 at 08:42:48PM -0800, Arjan van de Ven wrote: > Wanne bet there'll be devices that screw this up? THere's devices that even screwed > up the 64-256 region after all. I don't know if they 'screwed it up'. There are devices that misbehave when registers are read from pci config space. But this was never guaranteed to be a safe thing to do; it gradualy became clear that people expected to be able to read random registers and manufacturers responded accordingly, but I don't think you were ever guaranteed to be able to peek at bits of config space arbitrarily. -- 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."