1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/r600_blit_kms.c b/drivers/gpu/drm/radeon/r600_blit_kms.c
index bbb0d615ac1c..1ebfd5a6dfec 100644
--- a/drivers/gpu/drm/radeon/r600_blit_kms.c
+++ b/drivers/gpu/drm/radeon/r600_blit_kms.c
@@ -550,6 +550,12 @@ int r600_blit_prepare_copy(struct radeon_device *rdev, int size_bytes)
         int r;
         int ring_size;
         int max_size;
+        /* loops of emits 64 + fence emit possible */
+        int dwords_per_loop = 76;
+
+        /* set_render_target emits 2 extra dwords on rv6xx */
+        if (rdev->family > CHIP_R600 && rdev->family < CHIP_RV770)
+                dwords_per_loop += 2;
 
         /* 8 bpp vs 32 bpp for xfer unit */
         if (size_bytes & 3)
@@ -560,8 +566,7 @@ int r600_blit_prepare_copy(struct radeon_device *rdev, int size_bytes)
         r = r600_vb_ib_get(rdev);
         WARN_ON(r);
 
-        /* loops of emits 64 + fence emit possible */
-        ring_size = ((size_bytes + max_size) / max_size) * 78;
+        ring_size = ((size_bytes + max_size) / max_size) * dwords_per_loop;
         /* set default  + shaders */
         ring_size += 40; /* shaders + def state */
         ring_size += 3; /* fence emit for VB IB */