Re: [PATCH 3.13 08/32] PCI: Enable INTx in pci_reenable_device() only when MSI/MSI-X not enabled

Greg Kroah-Hartman
2014-04-22T19:15:19Z

On Mon, Apr 21, 2014 at 03:24:29PM +0100, Ben Hutchings wrote:
> On Sun, 2014-04-20 at 19:13 -0700, Greg Kroah-Hartman wrote:
> > 3.13-stable review patch. If anyone has any objections, please let me know.
> >
> > ------------------
> >
> > From: Bjorn Helgaas <bhelgaas@google.com>
> >
> > commit 866d54177b4e671cd52bed1fb487d140d7b691f5 upstream.
> >
> > Andreas reported that after 1f42db786b14 ("PCI: Enable INTx if BIOS left
> > them disabled"), pciehp surprise removal stopped working.
> >
> > This happens because pci_reenable_device() on the hotplug bridge (used in
> > the pciehp_configure_device() path) clears the Interrupt Disable bit, which
> > apparently breaks the bridge's MSI hotplug event reporting.
> >
> > Previously we cleared the Interrupt Disable bit in do_pci_enable_device(),
> > which is used by both pci_enable_device() and pci_reenable_device(). But
> > we use pci_reenable_device() after the driver may have enabled MSI or
> > MSI-X, and we *set* Interrupt Disable as part of enabling MSI/MSI-X.
> >
> > This patch clears Interrupt Disable only when MSI/MSI-X has not been
> > enabled.
> >
> > Fixes: 1f42db786b14 PCI: Enable INTx if BIOS left them disabled
> > Link: https://bugzilla.kernel.org/show_bug.cgi?id=71691
> > Reported-and-tested-by: Andreas Noever <andreas.noever@gmail.com>
> > Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> > CC: Sarah Sharp <sarah.a.sharp@linux.intel.com>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> >
> > ---
> > drivers/pci/pci.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > --- a/drivers/pci/pci.c
> > +++ b/drivers/pci/pci.c
> > @@ -1134,6 +1134,9 @@ static int do_pci_enable_device(struct p
> > if (dev->msi_enabled || dev->msix_enabled)
> > return 0;
> >
> > + if (dev->msi_enabled || dev->msix_enabled)
> > + return 0;
> > +
>
> This fix seems to have been applied to two upstream branches and you
> have already applied one instance.

Good catch, I've now removed it, thanks.

greg k-h