static void n_tty_check_throttle(struct tty_struct *tty)
{
	if (tty->driver->type == TTY_DRIVER_TYPE_PTY)
		return;
	/*
	 * Check the remaining room for the input canonicalization
	 * mode.  We don't want to throttle the driver if we're in
	 * canonical mode and don't have a newline yet!
	 */
	while (1) {
		int throttled;
		tty_set_flow_change(tty, TTY_THROTTLE_SAFE);
		if (receive_room(tty) >= TTY_THRESHOLD_THROTTLE)
			break;
		throttled = tty_throttle_safe(tty);
		if (!throttled)
			break;
	}
	__tty_set_flow_change(tty, 0);
}
Unknown