intel-iommu: Workaround IOTLB hang on Ironlake GPU

To work around a hardware issue, we have to submit IOTLB flushes while
the graphics engine is idle. The graphics driver will (we hope) go to
great lengths to ensure that it gets that right on the affected
chipset(s)... so let's not screw it over by deferring the unmap and
doing it later. That wouldn't be very helpful.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
This commit is contained in:
David Woodhouse 2011-10-17 15:51:52 -07:00 committed by Keith Packard
parent 130c2561de
commit d15bf23bc0
1 changed files with 5 additions and 1 deletions

View File

@ -3950,7 +3950,11 @@ static void __devinit quirk_calpella_no_shadow_gtt(struct pci_dev *dev)
if (!(ggc & GGC_MEMORY_VT_ENABLED)) {
printk(KERN_INFO "DMAR: BIOS has allocated no shadow GTT; disabling IOMMU for graphics\n");
dmar_map_gfx = 0;
}
} else if (dmar_map_gfx) {
/* we have to ensure the gfx device is idle before we flush */
printk(KERN_INFO "DMAR: Disabling batched IOTLB flush on Ironlake\n");
intel_iommu_strict = 1;
}
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0040, quirk_calpella_no_shadow_gtt);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0044, quirk_calpella_no_shadow_gtt);