MAX_WAIT_USECS
if (kb8042_send_and_expect(kb8042, KB_SET_SCAN, KB_ACK, MAX_WAIT_USECS,
if (kb8042_send_and_expect(kb8042, 0, KB_ACK, MAX_WAIT_USECS, &err,
while (kb8042_is_input_avail(kb8042, MAX_WAIT_USECS, B_TRUE) &&