diff options
| -rw-r--r-- | drivers/gpu/drm/nouveau/nv50_fb.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/gpu/drm/nouveau/nv50_fb.c b/drivers/gpu/drm/nouveau/nv50_fb.c index a95e6941ba88..32611bd30e6d 100644 --- a/drivers/gpu/drm/nouveau/nv50_fb.c +++ b/drivers/gpu/drm/nouveau/nv50_fb.c @@ -6,10 +6,16 @@ int nv50_fb_init(struct drm_device *dev) { - /* This is needed to get meaningful information from 100c90 - * on traps. No idea what these values mean exactly. */ struct drm_nouveau_private *dev_priv = dev->dev_private; + /* Not a clue what this is exactly. Without pointing it at a + * scratch page, VRAM->GART blits with M2MF (as in DDX DFS) + * cause IOMMU "read from address 0" errors (rh#561267) + */ + nv_wr32(dev, 0x100c08, dev_priv->gart_info.sg_dummy_bus >> 8); + + /* This is needed to get meaningful information from 100c90 + * on traps. No idea what these values mean exactly. */ switch (dev_priv->chipset) { case 0x50: nv_wr32(dev, 0x100c90, 0x0707ff); |