drm/radeon: fix ring free alignment calculations

fd.o bz#21849

We were aligning to +16 dwords, instead of to the next 16dword
boundary in the ring. Fix the calculation to go to the next 16dword
boundary when space checking.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_cp.c b/drivers/gpu/drm/radeon/radeon_cp.c
index 77a7a4d84650..aff90bb96488 100644
--- a/drivers/gpu/drm/radeon/radeon_cp.c
+++ b/drivers/gpu/drm/radeon/radeon_cp.c
@@ -2185,9 +2185,9 @@ void radeon_commit_ring(drm_radeon_private_t *dev_priv)
 
         /* check if the ring is padded out to 16-dword alignment */
 
-        tail_aligned = dev_priv->ring.tail & 0xf;
+        tail_aligned = dev_priv->ring.tail & (RADEON_RING_ALIGN-1);
         if (tail_aligned) {
-                int num_p2 = 16 - tail_aligned;
+                int num_p2 = RADEON_RING_ALIGN - tail_aligned;
 
                 ring = dev_priv->ring.start;
                 /* pad with some CP_PACKET2 */