drm/omap: check if rotation is supported before commit

omapdrm is missing a check on the validity of the rotation property.
This leads to omapdrm possibly trying to use rotation on non-rotateable
framebuffer, which causes the overlay setup to fail.

This patch adds the necessary check to omap_plane_atomic_check().

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
diff --git a/drivers/gpu/drm/omapdrm/omap_plane.c b/drivers/gpu/drm/omapdrm/omap_plane.c
index d75b197..93ee538 100644
--- a/drivers/gpu/drm/omapdrm/omap_plane.c
+++ b/drivers/gpu/drm/omapdrm/omap_plane.c
@@ -177,6 +177,12 @@
 	if (state->crtc_y + state->crtc_h > crtc_state->adjusted_mode.vdisplay)
 		return -EINVAL;
 
+	if (state->fb) {
+		if (state->rotation != BIT(DRM_ROTATE_0) &&
+		    !omap_framebuffer_supports_rotation(state->fb))
+			return -EINVAL;
+	}
+
 	return 0;
 }