Input: remove useless synchronize_rcu() calls

There is no need to call synchronize_rcu() after a list insertion,
or a NULL->ptr assignment.

However, the reverse operations do need this call.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

4 files changed, 0 insertions, 5 deletions

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 75c4e8683033..be0921ef6b52 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -164,7 +164,6 @@ static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
                 return error;
 
         rcu_assign_pointer(evdev->grab, client);
-        synchronize_rcu();
 
         return 0;
 }
@@ -187,7 +186,6 @@ static void evdev_attach_client(struct evdev *evdev,
         spin_lock(&evdev->client_lock);
         list_add_tail_rcu(&client->node, &evdev->client_list);
         spin_unlock(&evdev->client_lock);
-        synchronize_rcu();
 }
 
 static void evdev_detach_client(struct evdev *evdev,
diff --git a/drivers/input/input.c b/drivers/input/input.c
index ebbceedc92f4..75e11c7b70fd 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -451,7 +451,6 @@ int input_grab_device(struct input_handle *handle)
         }
 
         rcu_assign_pointer(dev->grab, handle);
-        synchronize_rcu();
 
  out:
         mutex_unlock(&dev->mutex);
diff --git a/drivers/input/joydev.c b/drivers/input/joydev.c
index 5688b5c88f24..c24ec2d5f926 100644
--- a/drivers/input/joydev.c
+++ b/drivers/input/joydev.c
@@ -180,7 +180,6 @@ static void joydev_attach_client(struct joydev *joydev,
         spin_lock(&joydev->client_lock);
         list_add_tail_rcu(&client->node, &joydev->client_list);
         spin_unlock(&joydev->client_lock);
-        synchronize_rcu();
 }
 
 static void joydev_detach_client(struct joydev *joydev,
diff --git a/drivers/input/mousedev.c b/drivers/input/mousedev.c
index 7630273e9474..257e033986e4 100644
--- a/drivers/input/mousedev.c
+++ b/drivers/input/mousedev.c
@@ -508,7 +508,6 @@ static void mousedev_attach_client(struct mousedev *mousedev,
         spin_lock(&mousedev->client_lock);
         list_add_tail_rcu(&client->node, &mousedev->client_list);
         spin_unlock(&mousedev->client_lock);
-        synchronize_rcu();
 }
 
 static void mousedev_detach_client(struct mousedev *mousedev,