[PATCH] tty buffering stall fix

Prevent stalled processing of received data when a driver allocates tty
buffer space but does not immediately follow the allocation with more data
and a call to schedule receive tty processing.  (example: hvc_console) This
bug was introduced by the first locking patch for the new tty buffering.

Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/tty.h

@@ -58,6 +58,8 @@ struct tty_buffer {
 	int used;
 	int size;
 	int active;
+	int commit;
+	int read;
 	/* Data points here */
 	unsigned long data[0];
 };