Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757049AbZCGBIT (ORCPT ); Fri, 6 Mar 2009 20:08:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754427AbZCGBIG (ORCPT ); Fri, 6 Mar 2009 20:08:06 -0500 Received: from hera.kernel.org ([140.211.167.34]:54581 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754021AbZCGBID (ORCPT ); Fri, 6 Mar 2009 20:08:03 -0500 Message-ID: <49B1C8C1.4090304@kernel.org> Date: Fri, 06 Mar 2009 17:07:13 -0800 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: "H. Peter Anvin" CC: Jesse Barnes , Matthew Wilcox , Ingo Molnar , Andrew Morton , Thomas Gleixner , "linux-kernel@vger.kernel.org" , linux-pci@vger.kernel.org Subject: Re: [PATCH] x86/pci: try to detect host_bridge pci_cfg_space References: <49B1C50E.5010209@kernel.org> <49B1C69F.70904@zytor.com> <49B1C81B.5010904@zytor.com> In-Reply-To: <49B1C81B.5010904@zytor.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1169 Lines: 34 H. Peter Anvin wrote: > H. Peter Anvin wrote: >> Yinghai Lu wrote: >>> Impact: get correct pci_cfg_size for host_bridge >>> >>> more host bridges support 4k cfg, so check them directly >>> instead of quirks. >>> >>> Signed-off-by: Yinghai Lu >> >> I'm utterly confused by this. This is basically saying we should try >> to probe for an extended device space for every host bridge. >> Logically speaking, this is valid: if there is a valid path by which >> we can probe for byte 256 then it should succeed. >> >> HOWEVER, the same argument applies for *every single device*. So if >> this does indeed work, why should we limit it to host bridges? >> > > Looking at the code (as opposed to just the patch) made it a bit > clearer. The argument you're making here is that only host bridges are > known to have extended address space without also having a PCI-X > extension header, right? Yes. YH -- 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/