Input: evdev - Don't hold wakelock when no data is available to user-space

If there is no SYN_REPORT event in the buffer the buffer data is invisible
to user-space. The wakelock should not be held in this case.

(cherry picked from commit 7cc846069a8a9116d8c81526c459070eed0e3477 from
android.googlesource.com/common.git)

Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
Change-Id: I7555b190ff8e4e526291dd353c3c0291b05dfff2
Reviewed-on: http://git-master/r/78894
Reviewed-by: Automatic_Commit_Validation_User

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 6e7dd687d5c9..031195fa9297 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -62,7 +62,6 @@ static void evdev_pass_event(struct evdev_client *client,
 	/* Interrupts are disabled, just acquire the lock. */
 	spin_lock(&client->buffer_lock);
 
-	wake_lock_timeout(&client->wake_lock, 5 * HZ);
 	client->buffer[client->head++] = *event;
 	client->head &= client->bufsize - 1;
 
@@ -79,10 +78,12 @@ static void evdev_pass_event(struct evdev_client *client,
 		client->buffer[client->tail].value = 0;
 
 		client->packet_head = client->tail;
+		wake_unlock(&client->wake_lock);
 	}
 
 	if (event->type == EV_SYN && event->code == SYN_REPORT) {
 		client->packet_head = client->head;
+		wake_lock_timeout(&client->wake_lock, 5 * HZ);
 		kill_fasync(&client->fasync, SIGIO, POLL_IN);
 	}
 
@@ -385,7 +386,7 @@ static int evdev_fetch_next_event(struct evdev_client *client,
 	if (have_event) {
 		*event = client->buffer[client->tail++];
 		client->tail &= client->bufsize - 1;
-		if (client->head == client->tail)
+		if (client->packet_head == client->tail)
 			wake_unlock(&client->wake_lock);
 	}