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>
diff --git a/include/linux/tty.h b/include/linux/tty.h
index c36a76d..7f7121f 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -303,6 +303,8 @@
extern int tty_chars_in_buffer(struct tty_struct *tty);
extern int tty_write_room(struct tty_struct *tty);
extern void tty_driver_flush_buffer(struct tty_struct *tty);
+extern void tty_throttle(struct tty_struct *tty);
+extern void tty_unthrottle(struct tty_struct *tty);
extern int is_current_pgrp_orphaned(void);
extern struct pid *tty_get_pgrp(struct tty_struct *tty);
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index f80d73b..59f1c0b 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