ao_wakeup(&ao_stdin_ready);
#if HAS_SERIAL_SW_FLOW
/* If the fifo is nearly full, turn off RTS and wait
* for it to drain a bunch
*/
if (usart->gpio_rts && ao_fifo_mostly(usart->rx_fifo)) {
ao_wakeup(&ao_stdin_ready);
#if HAS_SERIAL_SW_FLOW
/* If the fifo is nearly full, turn off RTS and wait
* for it to drain a bunch
*/
if (usart->gpio_rts && ao_fifo_mostly(usart->rx_fifo)) {