From 7cbbb758d3c93b24b45b169af55440d2e7d5b7f6 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 11 May 2011 15:38:10 -0700
Subject: 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>

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 75c4e86..be0921e 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 ebbceed..75e11c7 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 5688b5c..c24ec2d 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 7630273..257e033 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,
-- 
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