diff --git a/shared-core/radeon_cp.c b/shared-core/radeon_cp.c
index 89d2a24..43ba689 100644
--- a/shared-core/radeon_cp.c
+++ b/shared-core/radeon_cp.c
@@ -16573,14 +16573,14 @@ static void radeon_cp_init_ring_buffer(struct drm_device * dev,
 #ifdef __BIG_ENDIAN
 	RADEON_WRITE(RADEON_CP_RB_CNTL,
 		     RADEON_BUF_SWAP_32BIT |
-		     (dev_priv->ring.fetch_size_l2ow << 18) |
-		     (dev_priv->ring.rptr_update_l2qw << 8) |
-		     dev_priv->ring.size_l2qw);
+		     ((dev_priv->ring.fetch_size_l2ow & 0x3) << 18) |
+		     ((dev_priv->ring.rptr_update_l2qw & 0x3f) << 8) |
+		     ((dev_priv->ring.size_l2qw & 0x3f) << 0));
 #else
 	RADEON_WRITE(RADEON_CP_RB_CNTL,
-		     (dev_priv->ring.fetch_size_l2ow << 18) |
-		     (dev_priv->ring.rptr_update_l2qw << 8) |
-		     dev_priv->ring.size_l2qw);
+		     ((dev_priv->ring.fetch_size_l2ow & 0x3) << 18) |
+		     ((dev_priv->ring.rptr_update_l2qw & 0x3f) << 8) |
+		     ((dev_priv->ring.size_l2qw & 0x3f) << 0));
 #endif
 
 	/* Start with assuming that writeback doesn't work */