1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index f8aadc3c2124..85fc2b1a124a 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -563,6 +563,14 @@ static int init_ring_common(struct intel_engine_cs *ring)
          * also enforces ordering), otherwise the hw might lose the new ring
          * register values. */
         I915_WRITE_START(ring, i915_gem_obj_ggtt_offset(obj));
+
+        /* WaClearRingBufHeadRegAtInit:ctg,elk */
+        if (I915_READ_HEAD(ring))
+                DRM_DEBUG("%s initialization failed [head=%08x], fudging\n",
+                          ring->name, I915_READ_HEAD(ring));
+        I915_WRITE_HEAD(ring, 0);
+        (void)I915_READ_HEAD(ring);
+
         I915_WRITE_CTL(ring,
                         ((ringbuf->size - PAGE_SIZE) & RING_NR_PAGES)
                         | RING_VALID);