On 7 April 2013 10:35, Poul-Henning Kamp <phk at phk.freebsd.dk> wrote: > > I think if you configure no irq at all, it will automatically > go to polled mode. > > Not sure if uart(4) can actually do that, sio(4) could. Yup, it does. No IRQ hint == polled mode. It'll say as much in the dmesg. Adrian