Merge branch 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6
* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
drm/i915: fix memory corruption with GM965 and >4GB RAM
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 17bd766..e33d9be 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1895,6 +1895,17 @@
if (IS_GEN2(dev))
dma_set_coherent_mask(&dev->pdev->dev, DMA_BIT_MASK(30));
+ /* 965GM sometimes incorrectly writes to hardware status page (HWS)
+ * using 32bit addressing, overwriting memory if HWS is located
+ * above 4GB.
+ *
+ * The documentation also mentions an issue with undefined
+ * behaviour if any general state is accessed within a page above 4GB,
+ * which also needs to be handled carefully.
+ */
+ if (IS_BROADWATER(dev) || IS_CRESTLINE(dev))
+ dma_set_coherent_mask(&dev->pdev->dev, DMA_BIT_MASK(32));
+
mmio_bar = IS_GEN2(dev) ? 1 : 0;
dev_priv->regs = pci_iomap(dev->pdev, mmio_bar, 0);
if (!dev_priv->regs) {
