[PATCH] drm/atomic: Don't reject reflect-only rotations

[Brian Starkey]

The check to reject combinations of multiple rotation angles is overly
restrictive and has the side-effect of also failing any rotation value
which consists only of reflections.

Fix this by relaxing the check to ignore values which contain no
rotation flags.

Fixes: 6e0c7c3358d4 ("drm/atomic: Reject attempts to use multiple rotation angles at once")
Signed-off-by: Brian Starkey <brian.starkey at arm.com>
---
 drivers/gpu/drm/drm_atomic.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 362e3ea..44f4030 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -846,7 +846,8 @@ int drm_atomic_plane_set_property(struct drm_plane *plane,
 	} else if (property == config->prop_src_h) {
 		state->src_h = val;
 	} else if (property == plane->rotation_property) {
-		if (!is_power_of_2(val & DRM_ROTATE_MASK))
+		if ((val & DRM_ROTATE_MASK) &&
+		    !is_power_of_2(val & DRM_ROTATE_MASK))
 			return -EINVAL;
 		state->rotation = val;
 	} else if (property == plane->zpos_property) {
-- 
1.7.9.5