drm/nv50: fix iommu errors caused by device reading from address 0

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Ben Skeggs 2010-06-07 13:59:40 +10:00 committed by Dave Airlie
parent 7504794448
commit 4eb3033c72

View file

@ -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);