Index: uspace/lib/usbdev/src/devdrv.c
===================================================================
--- uspace/lib/usbdev/src/devdrv.c	(revision 904dcc623f249cd32bbe93958edd8df7f1648136)
+++ uspace/lib/usbdev/src/devdrv.c	(revision 7fc260ffa62d86f99e8634cd65b022ec7332d201)
@@ -300,4 +300,15 @@
 
 	return rc;
+}
+
+/** Cleanup structure initialized via usb_device_retrieve_descriptors.
+ *
+ * @param[in] descriptors Where to store the descriptors.
+ */
+void usb_device_release_descriptors(usb_device_descriptors_t *descriptors)
+{
+	assert(descriptors);
+	free(descriptors->configuration);
+	descriptors->configuration = NULL;
 }
 
@@ -490,32 +501,4 @@
 }
 
-/** Initialize control pipe in a device.
- *
- * @param dev USB device in question.
- * @param errmsg Where to store error context.
- * @return
- */
-static int init_wire_and_ctrl_pipe(usb_device_t *dev, const char **errmsg)
-{
-	int rc;
-
-	rc = usb_device_connection_initialize_from_device(&dev->wire,
-	    dev->ddf_dev);
-	if (rc != EOK) {
-		*errmsg = "device connection initialization";
-		return rc;
-	}
-
-	rc = usb_pipe_initialize_default_control(&dev->ctrl_pipe,
-	    &dev->wire);
-	if (rc != EOK) {
-		*errmsg = "default control pipe initialization";
-		return rc;
-	}
-
-	return EOK;
-}
-
-
 /** Initialize new instance of USB device.
  *
@@ -533,4 +516,6 @@
 	assert(ddf_dev != NULL);
 
+	*errstr_ptr = NULL;
+
 	usb_dev->ddf_dev = ddf_dev;
 	usb_dev->driver_data = NULL;
@@ -540,6 +525,17 @@
 
 	/* Initialize backing wire and control pipe. */
-	int rc = init_wire_and_ctrl_pipe(usb_dev, errstr_ptr);
-	if (rc != EOK) {
+	int rc = usb_device_connection_initialize_from_device(
+	    &usb_dev->wire, ddf_dev);
+	if (rc != EOK) {
+		*errstr_ptr = "device connection initialization";
+		return rc;
+	}
+
+	/* This pipe was registered by the hub driver,
+	 * during device initialization. */
+	rc = usb_pipe_initialize_default_control(&usb_dev->ctrl_pipe,
+	    &usb_dev->wire);
+	if (rc != EOK) {
+		*errstr_ptr = "default control pipe initialization";
 		return rc;
 	}
@@ -552,19 +548,21 @@
 	    &usb_dev->descriptors);
 	if (rc != EOK) {
-		/* Nothing allocated, nothing to free. */
 		*errstr_ptr = "descriptor retrieval";
 		return rc;
 	}
 
-	/* Create alternate interfaces. We will silently ignore failure. */
-	//TODO Why ignore?
+	/* Create alternate interfaces. We will silently ignore failure.
+	 * We might either control one interface or an entire device,
+	 * it makes no sense to speak about alternate interfaces when
+	 * controlling a device. */
 	usb_alternate_interfaces_init(&usb_dev->alternate_interfaces,
 	    usb_dev->descriptors.configuration,
 	    usb_dev->descriptors.configuration_size, usb_dev->interface_no);
 
+	/* TODO Add comment here. */
 	rc = initialize_other_pipes(endpoints, usb_dev, 0);
 	if (rc != EOK) {
 		/* Full configuration descriptor is allocated. */
-		free(usb_dev->descriptors.configuration);
+		usb_device_release_descriptors(&usb_dev->descriptors);
 		/* Alternate interfaces may be allocated */
 		usb_alternate_interfaces_deinit(&usb_dev->alternate_interfaces);
@@ -573,6 +571,4 @@
 	}
 
-	*errstr_ptr = NULL;
-
 	return EOK;
 }
@@ -591,5 +587,5 @@
 
 		usb_alternate_interfaces_deinit(&dev->alternate_interfaces);
-		free(dev->descriptors.configuration);
+		usb_device_release_descriptors(&dev->descriptors);
 		free(dev->driver_data);
 	}
Index: uspace/lib/usbdev/src/pipes.c
===================================================================
--- uspace/lib/usbdev/src/pipes.c	(revision 904dcc623f249cd32bbe93958edd8df7f1648136)
+++ uspace/lib/usbdev/src/pipes.c	(revision 7fc260ffa62d86f99e8634cd65b022ec7332d201)
@@ -75,4 +75,5 @@
 int usb_device_get_assigned_interface(const ddf_dev_t *device)
 {
+	assert(device);
 	async_sess_t *parent_sess =
 	    devman_parent_device_connect(EXCHANGE_ATOMIC, device->handle,