From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:13068 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753380AbaEDKko (ORCPT ); Sun, 4 May 2014 06:40:44 -0400 Message-ID: <1399200049.4302.3.camel@localhost.localdomain> Subject: Re: [PATCH] PCI/shpchp: fix a bus speed issue on hotplug From: Marcel Apfelbaum To: Bjorn Helgaas Cc: "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Matthew Wilcox , "Michael S. Tsirkin" Date: Sun, 04 May 2014 13:40:49 +0300 In-Reply-To: References: <1398954948-24219-1-git-send-email-marcel.a@redhat.com> <1398968025.18595.22.camel@localhost.localdomain> <1398970625.18595.24.camel@localhost.localdomain> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org List-ID: On Thu, 2014-05-01 at 14:00 -0600, Bjorn Helgaas wrote: > On Thu, May 1, 2014 at 12:57 PM, Marcel Apfelbaum > wrote: > > On Thu, 2014-05-01 at 21:13 +0300, Marcel Apfelbaum wrote: > >> On Thu, 2014-05-01 at 12:02 -0600, Bjorn Helgaas wrote: > >> > On Thu, May 1, 2014 at 8:35 AM, Marcel Apfelbaum wrote: > >> > > When a board is added, the shpchp driver checks if there > >> > > is a mismatch between the bridge's adapter and the bus speed. > >> > > If there is, it sets the subordinate speed (if there is no device on it). > >> > > > >> > > However, it takes the reference of the board speed from the primary bus > >> > > and not from the subordinate. If the primary bus is PCI and not PCIX/PCIe, > >> > > its speed is not updated and remains 0xff. As a result hotplug fails > >> > > with error: "Speed of bus ff and adapter 0 mismatch". > >> > > >> > It'd be cool to have a bugzilla for this with lspci and dmesg output. > >> > I'll also have to check the other hotplug drivers for similar issues, > >> > unless you've already done that. > >> I'll open a BZ with the details, sure. > > Done: https://bugzilla.kernel.org/show_bug.cgi?id=75251 > > If you need further details, please let me know. > > Thanks. Would you mind attaching the "lspci -vv" output? That should > show more details, including the information used to compute the bus > speed. > > Also, you checked the "regression" box. Can you confirm that and > identify a known-working kernel? If we know which kernels are broken, > we can potentially mark the fix to be backported to them. I checked 2.6.24-26-generic that comes with Ubuntu 8.04 and it works OK. So we have a working version. I hope it helps, Marcel > > Bjorn