[PATCH 2/7] drm/atomic: Reject attempts to use multiple rotation angles at once

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

The rotation property should only accept exactly one rotation angle
at once. Let's reject attempts to set none or multiple angles.

Testcase: igt/kms_rotation_crc/bad-rotation
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/drm_atomic.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 3cee084e9d28..5f0002897862 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -711,6 +711,8 @@ int drm_atomic_plane_set_property(struct drm_plane *plane,
 	} else if (property == config->prop_src_h) {
 		state->src_h = val;
 	} else if (property == config->rotation_property) {
+		if (!is_power_of_2(val & DRM_ROTATE_MASK))
+			return -EINVAL;
 		state->rotation = val;
 	} else if (plane->funcs->atomic_set_property) {
 		return plane->funcs->atomic_set_property(plane, state,
-- 
2.7.4