Comment 4 for bug 911236

@Joseph: I tried 3.2.0-4.10 but still had the errors:
Ubuntu 3.2.0-4.10-generic 3.2.0-rc5
[ 88.263384] DRHD: handling fault status reg 2
[ 88.263396] DMAR:[DMA Write] Request device [00:02.0] fault addr 7ff1c7000
[ 88.263399] DMAR:[fault reason 05] PTE Write access is not set

@Leann: I tried intel_iommu=igfx_off on both the rc5 and the current rc7 kernel and did not have the errors:
Ubuntu 3.2.0-4.10-generic 3.2.0-rc5
[ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-3.2.0-4-generic root=UUID=88689ad2-74b5-442c-9290-8ae60b63e16b ro quiet splash intel_iommu=igfx_off vt.handoff=7
[ 0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-3.2.0-4-generic root=UUID=88689ad2-74b5-442c-9290-8ae60b63e16b ro quiet splash intel_iommu=igfx_off vt.handoff=7

Ubuntu 3.2.0-7.13-generic 3.2.0-rc7
[ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-3.2.0-7-generic root=UUID=88689ad2-74b5-442c-9290-8ae60b63e16b ro quiet splash intel_iommu=igfx_off vt.handoff=7
[ 0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-3.2.0-7-generic root=UUID=88689ad2-74b5-442c-9290-8ae60b63e16b ro quiet splash intel_iommu=igfx_off vt.handoff=7

I will now use 'intel_iommu=igfx_off' as the workaround.