Re: [3.9 stable PATCH] iommu/vt-d: add quirk for broken interrupt remapping on 55XX chipsets

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Jun 26, 2013 at 09:26:35AM -0400, Neil Horman wrote:
> A few years back intel published a spec update:
> http://www.intel.com/content/dam/doc/specification-update/5520-and-5500-chipset-ioh-specification-update.pdf
> 
> For the 5520 and 5500 chipsets which contained an errata (specificially errata
> 53), which noted that these chipsets can't properly do interrupt remapping, and
> as a result the recommend that interrupt remapping be disabled in bios.  While
> many vendors have a bios update to do exactly that, not all do, and of course
> not all users update their bios to a level that corrects the problem.  As a
> result, occasionally interrupts can arrive at a cpu even after affinity for that
> interrupt has be moved, leading to lost or spurrious interrupts (usually
> characterized by the message:
> kernel: do_IRQ: 7.71 No irq handler for vector (irq -1)
> 
> There have been several incidents recently of people seeing this error, and
> investigation has shown that they have system for which their BIOS level is such
> that this feature was not properly turned off.  As such, it would be good to
> give them a reminder that their systems are vulnurable to this problem.  For
> details of those that reported the problem, please see:
> https://bugzilla.redhat.com/show_bug.cgi?id=887006
> 
> [ Joerg: Removed CONFIG_IRQ_REMAP ifdef from early-quirks.c ]
> 
> Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
> CC: Prarit Bhargava <prarit@redhat.com>
> CC: Don Zickus <dzickus@redhat.com>
> CC: Don Dutile <ddutile@redhat.com>
> CC: Bjorn Helgaas <bhelgaas@google.com>
> CC: Asit Mallick <asit.k.mallick@intel.com>
> CC: David Woodhouse <dwmw2@infradead.org>
> CC: linux-pci@vger.kernel.org
> CC: Joerg Roedel <joro@8bytes.org>
> CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> CC: Arkadiusz Miskiewicz <arekm@maven.pl>
> CC: Greg KH <gregkh@linuxfoundation.org>
> Signed-off-by: Joerg Roedel <joro@8bytes.org>
> ---
>  arch/x86/include/asm/irq_remapping.h |  3 +++
>  arch/x86/kernel/early-quirks.c       | 20 ++++++++++++++++++++
>  drivers/iommu/intel_irq_remapping.c  | 10 ++++++++++
>  drivers/iommu/irq_remapping.c        |  6 ++++++
>  drivers/iommu/irq_remapping.h        |  2 ++
>  5 files changed, 41 insertions(+)

Please let me know what the git commit id of the patch you are asking to
be applied is, in Linus's tree.  Otherwise I'll just assume you are
trying to get a patch into a stable branch that isn't in Linus's tree,
which isn't allowed, and I know you know better than to try to do that
:)

thanks,

greg k-h