usbgem_mac_stop
static int usbgem_mac_stop(struct usbgem_dev *, int, boolean_t);
(void) usbgem_mac_stop(dp, MAC_STATE_STOPPED, STOP_GRACEFUL);
(void) usbgem_mac_stop(dp, MAC_STATE_DISCONNECTED, graceful);
(void) usbgem_mac_stop(dp, MAC_STATE_STOPPED, STOP_GRACEFUL);