drm/i915: Unroll wrapping of the ringbuffer.

The tail is quadword aligned, so we can add two MI_NOOP as a time.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 26362f8495a8..df8302a11eb5 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -682,9 +682,11 @@ int intel_wrap_ring_buffer(struct drm_device *dev,
         }
 
         virt = (unsigned int *)(ring->virtual_start + ring->tail);
-        rem /= 4;
-        while (rem--)
+        rem /= 8;
+        while (rem--) {
                 *virt++ = MI_NOOP;
+                *virt++ = MI_NOOP;
+        }
 
         ring->tail = 0;
         ring->space = ring->head - 8;