1 files changed, 14 insertions, 25 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index e6c7a4dfea51..9907d66becdd 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -40,14 +40,19 @@
  */
 #define CACHELINE_BYTES 64
 
-static inline int ring_space(struct intel_ring_buffer *ring)
+static inline int __ring_space(int head, int tail, int size)
 {
-        int space = (ring->head & HEAD_ADDR) - (ring->tail + I915_RING_FREE_SPACE);
+        int space = head - (tail + I915_RING_FREE_SPACE);
         if (space < 0)
-                space += ring->size;
+                space += size;
         return space;
 }
 
+static inline int ring_space(struct intel_ring_buffer *ring)
+{
+        return __ring_space(ring->head & HEAD_ADDR, ring->tail, ring->size);
+}
+
 static bool intel_ring_stopped(struct intel_ring_buffer *ring)
 {
         struct drm_i915_private *dev_priv = ring->dev->dev_private;
@@ -1482,7 +1487,7 @@ void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring)
 static int intel_ring_wait_request(struct intel_ring_buffer *ring, int n)
 {
         struct drm_i915_gem_request *request;
-        u32 seqno = 0, tail;
+        u32 seqno = 0;
         int ret;
 
         if (ring->last_retired_head != -1) {
@@ -1495,26 +1500,10 @@ static int intel_ring_wait_request(struct intel_ring_buffer *ring, int n)
         }
 
         list_for_each_entry(request, &ring->request_list, list) {
-                int space;
-
-                if (request->tail == -1)
-                        continue;
-
-                space = request->tail - (ring->tail + I915_RING_FREE_SPACE);
-                if (space < 0)
-                        space += ring->size;
-                if (space >= n) {
+                if (__ring_space(request->tail, ring->tail, ring->size) >= n) {
                         seqno = request->seqno;
-                        tail = request->tail;
                         break;
                 }
-
-                /* Consume this request in case we need more space than
-                 * is available and so need to prevent a race between
-                 * updating last_retired_head and direct reads of
-                 * I915_RING_HEAD. It also provides a nice sanity check.
-                 */
-                request->tail = -1;
         }
 
         if (seqno == 0)
@@ -1524,11 +1513,11 @@ static int intel_ring_wait_request(struct intel_ring_buffer *ring, int n)
         if (ret)
                 return ret;
 
-        ring->head = tail;
-        ring->space = ring_space(ring);
-        if (WARN_ON(ring->space < n))
-                return -ENOSPC;
+        i915_gem_retire_requests_ring(ring);
+        ring->head = ring->last_retired_head;
+        ring->last_retired_head = -1;
 
+        ring->space = ring_space(ring);
         return 0;
 }