1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index e05a0216cd9b..b106984c722a 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -663,14 +663,15 @@ gen6_add_request(struct intel_ring_buffer *ring)
         struct drm_device *dev = ring->dev;
         struct drm_i915_private *dev_priv = dev->dev_private;
         struct intel_ring_buffer *useless;
-        int i, ret;
+        int i, ret, num_dwords = 4;
 
-        ret = intel_ring_begin(ring, ((I915_NUM_RINGS-1) *
-                                      MBOX_UPDATE_DWORDS) +
-                                      4);
+        if (i915_semaphore_is_enabled(dev))
+                num_dwords += ((I915_NUM_RINGS-1) * MBOX_UPDATE_DWORDS);
+#undef MBOX_UPDATE_DWORDS
+
+        ret = intel_ring_begin(ring, num_dwords);
         if (ret)
                 return ret;
-#undef MBOX_UPDATE_DWORDS
 
         for_each_ring(useless, dev_priv, i) {
                 u32 mbox_reg = ring->signal_mbox[i];