USB CDC ACM: Notification endpoint does seem to be needed.

src/usb/cdc_acm.c

@@ -92,7 +92,7 @@ bool_t cdc_acm_handle_class_request(void)
 
 bool_t cdc_acm_set_configuration(void)
 {
-    /* Set up endpoints: XXX Do we need the Notification Element? */
+    /* Set up endpoints. */
     usb_configure_ep(0x81, 0,  0); /* Notification Element (D->H) */
     usb_configure_ep(0x02, 0, 64); /* Bulk Pipe (H->D) */
     usb_configure_ep(0x82, 0, 64); /* Bulk Pipe (D->H) */

src/usb/config.c

@@ -72,7 +72,7 @@ const uint8_t config_descriptor[] __aligned(2) = {
 /* CDC Data interface */
     0x09, /* 0 bLength */
     DESC_INTERFACE, /* 1 bDescriptorType */
-    0x01, /* 2 bInterfacecNumber */
+    0x01, /* 2 bInterfaceNumber */
     0x00, /* 3 bAlternateSetting */
     0x02, /* 4 bNumEndpoints */
     USB_CLASS_CDC_DATA, /* 5 bInterfaceClass */