TTY_BLOCK
flags = (tty->flags & TTY_BLOCK);
tty->flags &= ~TTY_BLOCK;
if (n != 0 || (tty->flags & TTY_BLOCK)) {
tflags = tty->flags & (TTY_BLOCK|TTY_FREEZE|TTY_NOCURSOR);
tty->flags = (tty->flags & ~(TTY_BLOCK|TTY_FREEZE))|TTY_NOCURSOR;
tty->flags = (tty->flags & ~(TTY_BLOCK|TTY_FREEZE|TTY_NOCURSOR))|tflags;
if (tty->flags & TTY_BLOCK)
if (tty->flags & TTY_BLOCK)
tty->flags &= ~TTY_BLOCK;
if (tty->flags & TTY_BLOCK)
tty->flags |= TTY_BLOCK;
if (tty->flags & TTY_BLOCK)
tty->flags &= ~(TTY_NOCURSOR|TTY_FREEZE|TTY_BLOCK|TTY_TIMER);
tty->flags &= ~TTY_BLOCK;
if (tty->flags & TTY_BLOCK) {