[Intel-gfx] [PATCH] drm/i915: clarify gen2 pageflip cmd

[Daniel Vetter]

I've reviewed gen2 pageflip code do hunt down multple prepare pageflip
issues. The only thing I've found is a slight but functionally
meaningless confusion about the length of the mi cmd.

Fix it up and add a comment about what this dword should be (according
to docs at least).

Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/intel_display.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5ba19df..417661b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -7291,7 +7291,7 @@ static int intel_gen2_queue_flip(struct drm_device *dev,
 		 MI_DISPLAY_FLIP_PLANE(intel_crtc->plane));
 	OUT_RING(fb->pitches[0]);
 	OUT_RING(obj->gtt_offset + offset);
-	OUT_RING(MI_NOOP);
+	OUT_RING(0); /* aux display base address, unused */
 	ADVANCE_LP_RING();
 out:
 	return ret;
-- 
1.7.8.3