cfsetspeed
int cfsetspeed(struct termios *, speed_t);
cfsetspeed(&cntrl, speed);
cfsetspeed(&ttybuf, pp->baud_rate);
if (cfsetspeed(&tio, B0) == -1 || tcsetattr(p->fd, TCSANOW, &tio) == -1)
if (cfsetspeed(&ios, UnsignedToSpeed(p->cfg.speed)) == -1)