Index: uspace/drv/bus/usb/usbmid/usbmid.c
===================================================================
--- uspace/drv/bus/usb/usbmid/usbmid.c	(revision d5c1051faf4391647834d99babdd4a44ee5d9700)
+++ uspace/drv/bus/usb/usbmid/usbmid.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -51,5 +51,5 @@
  * @return Error code.
  */
-static int usb_iface_device_handle(ddf_fun_t *fun, devman_handle_t *handle)
+static errno_t usb_iface_device_handle(ddf_fun_t *fun, devman_handle_t *handle)
 {
 	assert(fun);
@@ -61,5 +61,5 @@
 
 /** Callback for DDF USB get interface. */
-static int usb_iface_iface_no(ddf_fun_t *fun, int *iface_no)
+static errno_t usb_iface_iface_no(ddf_fun_t *fun, int *iface_no)
 {
 	usbmid_interface_t *iface = ddf_fun_data_get(fun);
@@ -83,9 +83,9 @@
 };
 
-int usbmid_interface_destroy(usbmid_interface_t *mid_iface)
+errno_t usbmid_interface_destroy(usbmid_interface_t *mid_iface)
 {
 	assert(mid_iface);
 	assert_link_not_used(&mid_iface->link);
-	const int ret = ddf_fun_unbind(mid_iface->fun);
+	const errno_t ret = ddf_fun_unbind(mid_iface->fun);
 	if (ret != EOK) {
 		return ret;
@@ -103,5 +103,5 @@
  * @return Error code.
  */
-int usbmid_spawn_interface_child(usb_device_t *parent,
+errno_t usbmid_spawn_interface_child(usb_device_t *parent,
     usbmid_interface_t **iface_ret,
     const usb_standard_device_descriptor_t *device_descriptor,
@@ -110,5 +110,5 @@
 	ddf_fun_t *child = NULL;
 	char *child_name = NULL;
-	int rc;
+	errno_t rc;
 
 	/*