diff --git a/drivers/base/core.c b/drivers/base/core.c
index ef55df3..b56a0ba 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1345,6 +1345,8 @@
  * 'module' symlink which points to the @owner directory
  * in sysfs.
  *
+ * Returns &struct device pointer on success, or ERR_PTR() on error.
+ *
  * Note: You probably want to use root_device_register().
  */
 struct device *__root_device_register(const char *name, struct module *owner)
@@ -1432,6 +1434,8 @@
  * Any further sysfs files that might be required can be created using this
  * pointer.
  *
+ * Returns &struct device pointer on success, or ERR_PTR() on error.
+ *
  * Note: the struct class passed to this function must have previously
  * been created with a call to class_create().
  */
@@ -1492,6 +1496,8 @@
  * Any further sysfs files that might be required can be created using this
  * pointer.
  *
+ * Returns &struct device pointer on success, or ERR_PTR() on error.
+ *
  * Note: the struct class passed to this function must have previously
  * been created with a call to class_create().
  */