Input: evdev - indicate buffer overrun with SYN_DROPPED

Add a new EV_SYN code, SYN_DROPPED, to inform the client when input
events have been dropped from the evdev input buffer due to a
buffer overrun.  The client should use this event as a hint to
reset its state or ignore all following events until the next
packet begins.

Signed-off-by: Jeff Brown <jeffbrown@android.com>
[dtor@mail.ru: Implement Henrik's suggestion and drop old events in
 case of overflow.]
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/input.h b/include/linux/input.h
index 0cc25e4ce2ab..73a8c6ee595b 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -167,6 +167,7 @@ struct input_keymap_entry {
 #define SYN_REPORT              0
 #define SYN_CONFIG              1
 #define SYN_MT_REPORT           2
+#define SYN_DROPPED             3
 
 /*
  * Keys and buttons