UART_CHNL_INT_STS
while ((le32toh(uartaddr[UART_CHNL_INT_STS / 4]) & STS_TEMPTY) == 0)
int_sts = bus_space_read_4(iot, ioh, UART_CHNL_INT_STS);
bus_space_write_4(iot, ioh, UART_CHNL_INT_STS, int_sts);
bus_space_write_4(iot, ioh, UART_CHNL_INT_STS, INT_TIMEOUT);
sts = bus_space_read_4(iot, ioh, UART_CHNL_INT_STS);
bus_space_write_4(iot, ioh, UART_CHNL_INT_STS, sts);
bus_space_write_4(regsp->ur_iot, regsp->ur_ioh, UART_CHNL_INT_STS, 0xffff);