@ -243,8 +243,8 @@ void MarlinSerial::flush(void) {
// register empty flag ourselves. If it is set, pretend an
// interrupt has happened and call the handler to free up
// space for us.
if(TEST(M_UCSRxA, M_UDREx))
_tx_udr_empty_irq();
if (TEST(M_UCSRxA, M_UDREx))
} else {
// nop, the interrupt handler will free up space for us
}