[Intel-gfx] [PATCH 2/2] drm/i915: Limit calling mark-busy only for potential scanouts

[Chris Wilson]

The principle of intel_mark_busy() is that we want to spot the
transition of when the display engine is being used in order to bump
powersaving modes and increase display clocks. As such it is only
important when the display is changing, i.e. when rendering to the
scanout or other sprite/plane, and these are characterised by being
pinned.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 451efa3..10bb075 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -979,7 +979,8 @@ i915_gem_execbuffer_move_to_active(struct list_head *objects,
 			obj->pending_gpu_write = true;
 			list_move_tail(&obj->gpu_write_list,
 				       &ring->gpu_write_list);
-			intel_mark_busy(ring->dev, obj);
+			if (obj->pin_count) /* check for potential scanout */
+				intel_mark_busy(ring->dev, obj);
 		}
 
 		trace_i915_gem_object_change_domain(obj, old_read, old_write);
-- 
1.7.10