[PATCH 38/58] drm/i915: Extend the priority boosting for the display with a deadline

[Chris Wilson]

For a modeset/pageflip, there is a very precise deadline by which the
frame must be completed in order to hit the vblank and be shown. While
we don't pass along that exact information, we can at least inform the
scheduler that this request-chain needs to be completed asap.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/display/intel_display.c |  4 +++-
 drivers/gpu/drm/i915/gem/i915_gem_object.h   |  2 +-
 drivers/gpu/drm/i915/gem/i915_gem_wait.c     | 21 +++++++++++---------
 3 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index d28989310999..b8ed804ed254 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -15707,7 +15707,9 @@ intel_prepare_plane_fb(struct drm_plane *_plane,
 	if (ret)
 		return ret;
 
-	i915_gem_object_wait_priority(obj, 0, I915_PRIORITY_DISPLAY);
+	i915_gem_object_wait_priority(obj, 0,
+				      I915_PRIORITY_DISPLAY,
+				      ktime_get() /* next vblank? */);
 	i915_gem_object_flush_frontbuffer(obj, ORIGIN_DIRTYFB);
 
 	if (!new_plane_state->uapi.fence) { /* implicit fencing */
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index b106bc81c303..88b849c6f49d 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -517,7 +517,7 @@ int i915_gem_object_wait(struct drm_i915_gem_object *obj,
 			 long timeout);
 int i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
 				  unsigned int flags,
-				  int prio);
+				  int prio, ktime_t deadline);
 
 void __i915_gem_object_flush_frontbuffer(struct drm_i915_gem_object *obj,
 					 enum fb_op_origin origin);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_wait.c b/drivers/gpu/drm/i915/gem/i915_gem_wait.c
index 0d9dea4b0b65..d905d1111412 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_wait.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_wait.c
@@ -45,8 +45,7 @@ i915_gem_object_wait_reservation(struct dma_resv *resv,
 		unsigned int count, i;
 		int ret;
 
-		ret = dma_resv_get_fences_rcu(resv,
-							&excl, &count, &shared);
+		ret = dma_resv_get_fences_rcu(resv, &excl, &count, &shared);
 		if (ret)
 			return ret;
 
@@ -92,17 +91,20 @@ i915_gem_object_wait_reservation(struct dma_resv *resv,
 	return timeout;
 }
 
-static void __fence_set_priority(struct dma_fence *fence, int prio)
+static void
+__fence_set_prio(struct dma_fence *fence, int prio, ktime_t deadline)
 {
 	if (dma_fence_is_signaled(fence) || !dma_fence_is_i915(fence))
 		return;
 
 	local_bh_disable();
+	i915_request_set_deadline(to_request(fence),
+				  i915_sched_to_ticks(deadline));
 	i915_request_set_priority(to_request(fence), prio);
 	local_bh_enable(); /* kick the tasklets if queues were reprioritised */
 }
 
-static void fence_set_priority(struct dma_fence *fence, int prio)
+static void fence_set_prio(struct dma_fence *fence, int prio, ktime_t deadline)
 {
 	/* Recurse once into a fence-array */
 	if (dma_fence_is_array(fence)) {
@@ -110,16 +112,17 @@ static void fence_set_priority(struct dma_fence *fence, int prio)
 		int i;
 
 		for (i = 0; i < array->num_fences; i++)
-			__fence_set_priority(array->fences[i], prio);
+			__fence_set_prio(array->fences[i], prio, deadline);
 	} else {
-		__fence_set_priority(fence, prio);
+		__fence_set_prio(fence, prio, deadline);
 	}
 }
 
 int
 i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
 			      unsigned int flags,
-			      int prio)
+			      int prio,
+			      ktime_t deadline)
 {
 	struct dma_fence *excl;
 
@@ -134,7 +137,7 @@ i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
 			return ret;
 
 		for (i = 0; i < count; i++) {
-			fence_set_priority(shared[i], prio);
+			fence_set_prio(shared[i], prio, deadline);
 			dma_fence_put(shared[i]);
 		}
 
@@ -144,7 +147,7 @@ i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
 	}
 
 	if (excl) {
-		fence_set_priority(excl, prio);
+		fence_set_prio(excl, prio, deadline);
 		dma_fence_put(excl);
 	}
 	return 0;
-- 
2.20.1