x86: Adjust irq remapping quirk for older revisions of 5500/5520 chipsets
authorNeil Horman <nhorman@tuxdriver.com>
Wed, 12 Mar 2014 18:44:33 +0000 (14:44 -0400)
committerThomas Gleixner <tglx@linutronix.de>
Mon, 31 Mar 2014 20:07:01 +0000 (22:07 +0200)
commit6f8a1b335fde143b7407036e2368d3cd6eb55674
tree3d11db26ca7746a3f394145d075493350aef912f
parent4907cdca7210c5895311bddcf05a4c85b67d8566
x86: Adjust irq remapping quirk for older revisions of 5500/5520 chipsets

Commit 03bbcb2e7e2 (iommu/vt-d: add quirk for broken interrupt
remapping on 55XX chipsets) properly disables irq remapping on the
5500/5520 chipsets that don't correctly perform that feature.

However, when I wrote it, I followed the errata sheet linked in that
commit too closely, and explicitly tied the activation of the quirk to
revision 0x13 of the chip, under the assumption that earlier revisions
were not in the field.  Recently a system was reported to be suffering
from this remap bug and the quirk hadn't triggered, because the
revision id register read at a lower value that 0x13, so the quirk
test failed improperly.  Given this, it seems only prudent to adjust
this quirk so that any revision less than 0x13 has the quirk asserted.

[ tglx: Removed the 0x12 comparison of pci id 3405 as this is covered
     by the <= 0x13 check already ]

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1394649873-14913-1-git-send-email-nhorman@tuxdriver.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/kernel/early-quirks.c