3 files changed, 30 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 32feb2a27dfc..51470e96cdd4 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1886,7 +1886,7 @@ static void defer_request(struct i915_request *rq, struct list_head * const pl)
 				continue;
 
 			/* No waiter should start before its signaler */
-			GEM_BUG_ON(w->context->timeline->has_initial_breadcrumb &&
+			GEM_BUG_ON(i915_request_has_initial_breadcrumb(w) &&
 				   i915_request_started(w) &&
 				   !i915_request_completed(rq));
 
@@ -3493,6 +3493,7 @@ static int gen8_emit_init_breadcrumb(struct i915_request *rq)
 {
 	u32 *cs;
 
+	GEM_BUG_ON(i915_request_has_initial_breadcrumb(rq));
 	if (!i915_request_timeline(rq)->has_initial_breadcrumb)
 		return 0;
 
@@ -3519,6 +3520,8 @@ static int gen8_emit_init_breadcrumb(struct i915_request *rq)
 	/* Record the updated position of the request's payload */
 	rq->infix = intel_ring_offset(rq, cs);
 
+	__set_bit(I915_FENCE_FLAG_INITIAL_BREADCRUMB, &rq->fence.flags);
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 2d5b98549ddc..00b7c4eb3f32 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -951,6 +951,7 @@ __emit_semaphore_wait(struct i915_request *to,
 	u32 *cs;
 
 	GEM_BUG_ON(INTEL_GEN(to->i915) < 8);
+	GEM_BUG_ON(i915_request_has_initial_breadcrumb(to));
 
 	/* We need to pin the signaler's HWSP until we are finished reading. */
 	err = intel_timeline_read_hwsp(from, to, &hwsp_offset);
@@ -1000,6 +1001,9 @@ emit_semaphore_wait(struct i915_request *to,
 	if (!intel_context_use_semaphores(to->context))
 		goto await_fence;
 
+	if (i915_request_has_initial_breadcrumb(to))
+		goto await_fence;
+
 	if (!rcu_access_pointer(from->hwsp_cacheline))
 		goto await_fence;
 
@@ -1256,7 +1260,8 @@ __i915_request_await_execution(struct i915_request *to,
 	 * immediate execution, and so we must wait until it reaches the
 	 * active slot.
 	 */
-	if (intel_engine_has_semaphores(to->engine)) {
+	if (intel_engine_has_semaphores(to->engine) &&
+	    !i915_request_has_initial_breadcrumb(to)) {
 		err = __emit_semaphore_wait(to, from, from->fence.seqno - 1);
 		if (err < 0)
 			return err;
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index d8ce908e1346..98ae2dc82371 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -84,19 +84,26 @@ enum {
 	I915_FENCE_FLAG_PQUEUE,
 
 	/*
-	 * I915_FENCE_FLAG_SIGNAL - this request is currently on signal_list
+	 * I915_FENCE_FLAG_HOLD - this request is currently on hold
 	 *
-	 * Internal bookkeeping used by the breadcrumb code to track when
-	 * a request is on the various signal_list.
+	 * This request has been suspended, pending an ongoing investigation.
 	 */
-	I915_FENCE_FLAG_SIGNAL,
+	I915_FENCE_FLAG_HOLD,
 
 	/*
-	 * I915_FENCE_FLAG_HOLD - this request is currently on hold
+	 * I915_FENCE_FLAG_INITIAL_BREADCRUMB - this request has the initial
+	 * breadcrumb that marks the end of semaphore waits and start of the
+	 * user payload.
+	 */
+	I915_FENCE_FLAG_INITIAL_BREADCRUMB,
+
+	/*
+	 * I915_FENCE_FLAG_SIGNAL - this request is currently on signal_list
 	 *
-	 * This request has been suspended, pending an ongoing investigation.
+	 * Internal bookkeeping used by the breadcrumb code to track when
+	 * a request is on the various signal_list.
 	 */
-	I915_FENCE_FLAG_HOLD,
+	I915_FENCE_FLAG_SIGNAL,
 
 	/*
 	 * I915_FENCE_FLAG_NOPREEMPT - this request should not be preempted
@@ -390,6 +397,12 @@ static inline bool i915_request_in_priority_queue(const struct i915_request *rq)
 	return test_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
 }
 
+static inline bool
+i915_request_has_initial_breadcrumb(const struct i915_request *rq)
+{
+	return test_bit(I915_FENCE_FLAG_INITIAL_BREADCRUMB, &rq->fence.flags);
+}
+
 /**
  * Returns true if seq1 is later than seq2.
  */