drm/ast: Init cursors before creating modesetting structures

The cursor helpers reserve buffer objects in VRAM and update their
content. So although tied to modesetting, cursor helpers are more
of a memory manager. The modesetting's cursor plane requires this
functionality, so initialize cursors before modesetting.

While at it, also add an error check for ast_cursor_init().
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200702115029.5281-12-tzimmermann@suse.de

drivers/gpu/drm/ast/ast_mode.c

@@ -1073,6 +1073,10 @@ int ast_mode_init(struct drm_device *dev)
 	struct ast_private *ast = to_ast_private(dev);
 	int ret;
 
+	ret = ast_cursor_init(ast);
+	if (ret)
+		return ret;
+
 	memset(&ast->primary_plane, 0, sizeof(ast->primary_plane));
 	ret = drm_universal_plane_init(dev, &ast->primary_plane, 0x01,
 				       &ast_primary_plane_funcs,
@@ -1098,7 +1102,6 @@ int ast_mode_init(struct drm_device *dev)
 	drm_plane_helper_add(&ast->cursor_plane,
 			     &ast_cursor_plane_helper_funcs);
 
-	ast_cursor_init(ast);
 	ast_crtc_init(dev);
 	ast_encoder_init(dev);
 	ast_connector_init(dev);