From: Marcel Apfelbaum <marcel.a@redhat.com>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Matthew Wilcox <matthew@wil.cx>,
"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [PATCH] PCI/shpchp: fix a bus speed issue on hotplug
Date: Thu, 01 May 2014 21:13:45 +0300 [thread overview]
Message-ID: <1398968025.18595.22.camel@localhost.localdomain> (raw)
In-Reply-To: <CAErSpo4KLq7m8PXzAEhv20e29Wk=sAtageDf3CgziDLno0JUCw@mail.gmail.com>
On Thu, 2014-05-01 at 12:02 -0600, Bjorn Helgaas wrote:
> On Thu, May 1, 2014 at 8:35 AM, Marcel Apfelbaum <marcel.a@redhat.com> 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.
I didn't check the other hotplug drivers, but I do plan
to look into PCIe driver as part of QEMU's PCIe hotplug feature.
Thanks,
Marcel
>
> > Fixed that by checking the speed against the subordinate bus.
> >
> > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > ---
> > drivers/pci/hotplug/shpchp_ctrl.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/pci/hotplug/shpchp_ctrl.c b/drivers/pci/hotplug/shpchp_ctrl.c
> > index 5849927..6efc2ec 100644
> > --- a/drivers/pci/hotplug/shpchp_ctrl.c
> > +++ b/drivers/pci/hotplug/shpchp_ctrl.c
> > @@ -282,8 +282,8 @@ static int board_added(struct slot *p_slot)
> > return WRONG_BUS_FREQUENCY;
> > }
> >
> > - bsp = ctrl->pci_dev->bus->cur_bus_speed;
> > - msp = ctrl->pci_dev->bus->max_bus_speed;
> > + bsp = ctrl->pci_dev->subordinate->cur_bus_speed;
> > + msp = ctrl->pci_dev->subordinate->max_bus_speed;
> >
> > /* Check if there are other slots or devices on the same bus */
> > if (!list_empty(&ctrl->pci_dev->subordinate->devices))
> > --
> > 1.8.3.1
> >
next prev parent reply other threads:[~2014-05-01 18:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-01 14:35 [PATCH] PCI/shpchp: fix a bus speed issue on hotplug Marcel Apfelbaum
2014-05-01 15:43 ` Michael S. Tsirkin
2014-05-01 18:02 ` Bjorn Helgaas
2014-05-01 18:13 ` Marcel Apfelbaum [this message]
2014-05-01 18:57 ` Marcel Apfelbaum
2014-05-01 20:00 ` Bjorn Helgaas
2014-05-01 20:36 ` Marcel Apfelbaum
2014-05-04 10:40 ` Marcel Apfelbaum
2014-05-04 13:48 ` Ronen Hod
2014-05-04 14:07 ` Marcel Apfelbaum
2014-05-15 18:41 ` Bjorn Helgaas
2014-05-17 18:47 ` Michael S. Tsirkin
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