• Neil Horman's avatar
    iommu/vt-d: add quirk for broken interrupt remapping on 55XX chipsets · 03bbcb2e
    Neil Horman authored
    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: default avatarNeil 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 Miśkiewicz <arekm@maven.pl>
    Signed-off-by: default avatarJoerg Roedel <joro@8bytes.org>
    03bbcb2e
intel_irq_remapping.c 25.7 KB