* the line discipline are close to full, and it should somehow
* signal that no more characters should be sent to the tty.
*
- * Optional: Always invoke via tty_throttle();
+ * Optional: Always invoke via tty_throttle(), called under the
+ * termios lock.
*
* void (*unthrottle)(struct tty_struct * tty);
*
* that characters can now be sent to the tty without fear of
* overrunning the input buffers of the line disciplines.
*
- * Optional: Always invoke via tty_unthrottle();
+ * Optional: Always invoke via tty_unthrottle(), called under the
+ * termios lock.
*
* void (*stop)(struct tty_struct *tty);
*