From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from palinux.external.hp.com ([192.25.206.14]:40295 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756515Ab1KOUQr (ORCPT ); Tue, 15 Nov 2011 15:16:47 -0500 Date: Tue, 15 Nov 2011 13:16:46 -0700 From: Matthew Wilcox To: Prarit Bhargava Cc: Don Dutile , Bjorn Helgaas , James Paradis , linux-pci@vger.kernel.org, mstowe@redhat.com, matthew wilcox , jbarnes@virtuousgeek.org Subject: Re: [PATCH] pci: Workaround Stratus broken PCIE hierarchy Message-ID: <20111115201646.GG4387@parisc-linux.org> References: <4EBD73C8.8070407@redhat.com> <4EBD8714.30401@redhat.com> <4EC12962.2040105@redhat.com> <20111114181418.GE4387@parisc-linux.org> <4EC170E8.4070600@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <4EC170E8.4070600@redhat.com> Sender: linux-pci-owner@vger.kernel.org List-ID: On Mon, Nov 14, 2011 at 02:50:00PM -0500, Prarit Bhargava wrote: > This only works if there is a single Down bridge connected to a single Down bridge. What Stratus/NEC has is a single Up bridge (02:00.0) connected to a Up bridge (03:00.0) and a Down bridge (03:01.0), which we know to be illegal in PCIE. So the scan of the first bridge, 03:00.0 works and no fixup is done. The code still misses the second bridge, 03:01.0. I'd forgotten that the Down - Down link was at slot 1; I thought it was at slot 0. So this won't help. -- Matthew Wilcox Intel Open Source Technology Centre "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."