1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index b836721d3b13..20c7c77b3768 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -799,6 +799,21 @@ err_unreserve:
 }
 
 static int
+i915_request_await_start(struct i915_request *rq, struct i915_request *signal)
+{
+        if (list_is_first(&signal->ring_link, &signal->ring->request_list))
+                return 0;
+
+        signal = list_prev_entry(signal, ring_link);
+        if (i915_timeline_sync_is_later(rq->timeline, &signal->fence))
+                return 0;
+
+        return i915_sw_fence_await_dma_fence(&rq->submit,
+                                             &signal->fence, 0,
+                                             I915_FENCE_GFP);
+}
+
+static int
 emit_semaphore_wait(struct i915_request *to,
                     struct i915_request *from,
                     gfp_t gfp)
@@ -816,6 +831,10 @@ emit_semaphore_wait(struct i915_request *to,
                                                      &from->fence, 0,
                                                      I915_FENCE_GFP);
 
+        err = i915_request_await_start(to, from);
+        if (err < 0)
+                return err;
+
         err = i915_sw_fence_await_dma_fence(&to->semaphore,
                                             &from->fence, 0,
                                             I915_FENCE_GFP);