[Intel-gfx] [PATCH, rfc] drm/i915: Swap ggtt_vma during legacy cursor update

[Maarten Lankhorst]

Curious what people think of the approach. No need for all the heavy
handed locking, single swap is enough.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_cursor.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_cursor.c b/drivers/gpu/drm/i915/display/intel_cursor.c
index 8dd9dac3389c..a139b4e645ba 100644
--- a/drivers/gpu/drm/i915/display/intel_cursor.c
+++ b/drivers/gpu/drm/i915/display/intel_cursor.c
@@ -688,9 +688,8 @@ intel_legacy_cursor_update(struct drm_plane *_plane,
 	if (ret)
 		goto out_free;
 
-	ret = intel_plane_pin_fb(new_plane_state);
-	if (ret)
-		goto out_free;
+	/* magic trick! */
+	swap(new_plane_state->ggtt_vma, old_plane_state->ggtt_vma);
 
 	intel_frontbuffer_flush(to_intel_frontbuffer(new_plane_state->hw.fb),
 				ORIGIN_CURSOR_UPDATE);
-- 
2.34.1