drm/atomic: add all affected planes in drm_atomic_helper_check_modeset

Drivers may need to recalculate plane state when a modeset occurs,
not reliably adding them might cause hard to debug bugs.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_atomic_helper.c

@@ -429,6 +429,10 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
 		if (ret != 0)
 			return ret;
 
+		ret = drm_atomic_add_affected_planes(state, crtc);
+		if (ret != 0)
+			return ret;
+
 		num_connectors = drm_atomic_connectors_for_crtc(state,
 								crtc);