tty: add throttle/unthrottle helpers

Something Arjan suggested which allows us to clean up the code nicely

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index f80d73b690f6..59f1c0bd8f9c 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -100,6 +100,8 @@
  *      This routine notifies the tty driver that input buffers for
  *      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();
  * 
  * void (*unthrottle)(struct tty_struct * tty);
  *
@@ -107,6 +109,8 @@
  *      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();
+ *
  * void (*stop)(struct tty_struct *tty);
  *
  *      This routine notifies the tty driver that it should stop