From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 In-Reply-To: <1398970625.18595.24.camel@localhost.localdomain> References: <1398954948-24219-1-git-send-email-marcel.a@redhat.com> <1398968025.18595.22.camel@localhost.localdomain> <1398970625.18595.24.camel@localhost.localdomain> From: Bjorn Helgaas Date: Thu, 1 May 2014 14:00:41 -0600 Message-ID: Subject: Re: [PATCH] PCI/shpchp: fix a bus speed issue on hotplug To: marcel.a@redhat.com Cc: "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Matthew Wilcox , "Michael S. Tsirkin" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 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. Bjorn