drm/atomic: check mode_changed *after* atomic_check

The intention is that drivers can set crtc_state->mode_changed in their
atomic_check() fxns if they encounter a scenario that requires full
modeset.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_atomic_helper.c

@@ -331,7 +331,7 @@ mode_fixup(struct drm_atomic_state *state)
 }
 
 static int
-drm_atomic_helper_check_prepare(struct drm_device *dev,
+drm_atomic_helper_check_modeset(struct drm_device *dev,
 				struct drm_atomic_state *state)
 {
 	int ncrtcs = dev->mode_config.num_crtc;
@@ -428,10 +428,6 @@ int drm_atomic_helper_check(struct drm_device *dev,
 	int ncrtcs = dev->mode_config.num_crtc;
 	int i, ret = 0;
 
-	ret = drm_atomic_helper_check_prepare(dev, state);
-	if (ret)
-		return ret;
-
 	for (i = 0; i < nplanes; i++) {
 		struct drm_plane_helper_funcs *funcs;
 		struct drm_plane *plane = state->planes[i];
@@ -475,6 +471,10 @@ int drm_atomic_helper_check(struct drm_device *dev,
 		}
 	}
 
+	ret = drm_atomic_helper_check_modeset(dev, state);
+	if (ret)
+		return ret;
+
 	return ret;
 }
 EXPORT_SYMBOL(drm_atomic_helper_check);