From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752458AbXLVFaL (ORCPT ); Sat, 22 Dec 2007 00:30:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750885AbXLVF36 (ORCPT ); Sat, 22 Dec 2007 00:29:58 -0500 Received: from mx1.redhat.com ([66.187.233.31]:53606 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750798AbXLVF35 (ORCPT ); Sat, 22 Dec 2007 00:29:57 -0500 Message-ID: <476CA0CF.3090607@redhat.com> Date: Sat, 22 Dec 2007 00:29:51 -0500 From: Tony Camuso Reply-To: tcamuso@redhat.com User-Agent: Thunderbird 2.0.0.9 (X11/20071031) MIME-Version: 1.0 To: gregkh@suse.de, linux-kernel@vger.kernel.org, linux-pci@atrey.karlin.mff.cuni.cz, prarit@redhat.com, tcamuso@redhat.com Subject: Re: [PATCH 0/5]PCI: x86 MMCONFIG - a couple of corrections to the preamble References: <20071222024044.26026.1461.sendpatchset@dhcp83-188.boston.redhat.com> In-Reply-To: <20071222024044.26026.1461.sendpatchset@dhcp83-188.boston.redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Some corrections to the preamble. > The large amount of text is due to the nature of the > problem and the discussion it engendered on the lkml. Should say: The large amount of text in the explanation below is due to the nature of the problem and the discussion engendered on lkml by my first submission. > This patch-set detects the problem by comparing an MMCONFIG > read to a Legacy PCI config read of the vendor/device dword > of every device discovered during the PCI probing sequence. Actually, the patch doesn't do a pci config read of EVERY device discovered on every bus. Only on buses above a number defined by PCI_MMCFG_MAX_CHECK_BUS and whose parent bus's pci_bus.ops field points to pci_root_ops, which are mmconfig access routines in systems in which mmconfig is the default mechanism. In such cases where the parent bus pci_bus.ops field points to pci_legacy_ops, the current bus does not need to be probed, since its own pci_bus.ops field will inherit the pointer to pci_legacy_ops from its parent.