[PATCH v4 4/6] drm/atomic: Avoid unused-but-set-variable warning on for_each_old_plane_in_state

[Liu Ying]

Artifically use 'plane' and 'old_plane_state' to avoid 'not used' warning.
The precedent has already been set by other macros in the same file.

Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Liu Ying <victor.liu at nxp.com>
---
v3->v4:
* Add Daniel's A-b tag.

v2->v3:
* Add a missing blank line.

v1->v2:
* No change.

 include/drm/drm_atomic.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 54e051a..2e087d7 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -888,7 +888,10 @@ void drm_state_dump(struct drm_device *dev, struct drm_printer *p);
 	     (__i)++)							\
 		for_each_if ((__state)->planes[__i].ptr &&		\
 			     ((plane) = (__state)->planes[__i].ptr,	\
-			      (old_plane_state) = (__state)->planes[__i].old_state, 1))
+			      (void)(plane) /* Only to avoid unused-but-set-variable warning */, \
+			      (old_plane_state) = (__state)->planes[__i].old_state, \
+			      (void)(old_plane_state) /* Only to avoid unused-but-set-variable warning */, 1))
+
 /**
  * for_each_new_plane_in_state - iterate over all planes in an atomic update
  * @__state: &struct drm_atomic_state pointer
-- 
2.7.4