drm: radeon: Fix calculation of RB_RPTR_ADDR in non-AGP case.

The address needs to be a GART relative address, rather than a PCI
DMA address.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>

1 files changed, 4 insertions, 11 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_cp.c b/drivers/gpu/drm/radeon/radeon_cp.c
index 8a8a82a2c170..4a56e7d626a6 100644
--- a/drivers/gpu/drm/radeon/radeon_cp.c
+++ b/drivers/gpu/drm/radeon/radeon_cp.c
@@ -657,17 +657,10 @@ static void radeon_cp_init_ring_buffer(struct drm_device * dev,
         } else
 #endif
         {
-                struct drm_sg_mem *entry = dev->sg;
-                unsigned long tmp_ofs, page_ofs;
-
-                tmp_ofs = dev_priv->ring_rptr->offset -
-                                (unsigned long)dev->sg->virtual;
-                page_ofs = tmp_ofs >> PAGE_SHIFT;
-
-                RADEON_WRITE(RADEON_CP_RB_RPTR_ADDR, entry->busaddr[page_ofs]);
-                DRM_DEBUG("ring rptr: offset=0x%08lx handle=0x%08lx\n",
-                          (unsigned long)entry->busaddr[page_ofs],
-                          entry->handle + tmp_ofs);
+                RADEON_WRITE(RADEON_CP_RB_RPTR_ADDR,
+                             dev_priv->ring_rptr->offset
+                             - ((unsigned long) dev->sg->virtual)
+                             + dev_priv->gart_vm_start);
         }
 
         /* Set ring buffer size */