On Fri, 19 Nov 2021 15:37:19 +0530 M Chetan Kumar wrote:

+struct dentry *wwan_get_debugfs_dir(struct device *parent)
+{
+	struct wwan_device *wwandev;
+
+	if (WARN_ON(!parent))
+		return ERR_PTR(-EINVAL);

defensive programming, please drop this check

+	wwandev = wwan_dev_get_by_parent(parent);
+

please drop empty lines before calls and error checks

+	if (IS_ERR(wwandev))
+		return ERR_CAST(wwandev);
+
+	return wwandev->debugfs_dir;
+}
+EXPORT_SYMBOL_GPL(wwan_get_debugfs_dir);