Re: [PATCH v10] irq: add quirk for broken interrupt remapping on55XX chipsets

[Neil Horman]

On Thu, Apr 18, 2013 at 05:02:39PM +0200, Joerg Roedel wrote:
> On Tue, Apr 16, 2013 at 04:38:32PM -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
> > 
> > Signed-off-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
> > CC: Prarit Bhargava <prarit@xxxxxxxxxx>
> > CC: Don Zickus <dzickus@xxxxxxxxxx>
> > CC: Don Dutile <ddutile@xxxxxxxxxx>
> > CC: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> > CC: Asit Mallick <asit.k.mallick@xxxxxxxxx>
> > CC: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
> > CC: linux-pci@xxxxxxxxxxxxxxx
> > CC: Joerg Roedel <joro@xxxxxxxxxx>
> > CC: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> > CC: Arkadiusz MiÅkiewicz <arekm@xxxxxxxx>
> 
> Applied with some small changes to my x86/vt-d branch, thanks Neil.
> 
> 
> 
Thanks!
Neil

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