Commit 5aac4937 authored by Andrea Parri's avatar Andrea Parri Committed by Marcel Holtmann
Browse files

Bluetooth: Remove unnecessary smp_mb__{before,after}_atomic 



The barriers are unneeded; wait_woken() and woken_wake_function()
already provide us with the required synchronization: remove them
and document that we're relying on the (implicit) synchronization
provided by wait_woken() and woken_wake_function().

Signed-off-by: default avatarAndrea Parri <andrea.parri@amarulasolutions.com>
Reviewed-by: default avatarBrian Norris <computersforpeace@gmail.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent 1042caa7

net/bluetooth/bnep/core.c

+4 −3
Original line number Diff line number Diff line
@@ -489,9 +489,6 @@ static int bnep_session(void *arg) 


	add_wait_queue(sk_sleep(sk), &wait);

	while (1) {

		/* Ensure session->terminate is updated */

		smp_mb__before_atomic();



		if (atomic_read(&s->terminate))

			break;

		/* RX */
@@ -512,6 +509,10 @@ static int bnep_session(void *arg) 
				break;

		netif_wake_queue(dev);



		/*

		 * wait_woken() performs the necessary memory barriers

		 * for us; see the header comment for this primitive.

		 */

		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);

	}

	remove_wait_queue(sk_sleep(sk), &wait);

net/bluetooth/cmtp/core.c

+8 −6
Original line number Diff line number Diff line
@@ -288,9 +288,6 @@ static int cmtp_session(void *arg) 


	add_wait_queue(sk_sleep(sk), &wait);

	while (1) {

		/* Ensure session->terminate is updated */

		smp_mb__before_atomic();



		if (atomic_read(&session->terminate))

			break;

		if (sk->sk_state != BT_CONNECTED)
@@ -306,6 +303,10 @@ static int cmtp_session(void *arg) 


		cmtp_process_transmit(session);



		/*

		 * wait_woken() performs the necessary memory barriers

		 * for us; see the header comment for this primitive.

		 */

		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);

	}

	remove_wait_queue(sk_sleep(sk), &wait);
@@ -431,9 +432,10 @@ int cmtp_del_connection(struct cmtp_conndel_req *req) 
		/* Stop session thread */

		atomic_inc(&session->terminate);



		/* Ensure session->terminate is updated */

		smp_mb__after_atomic();



		/*

		 * See the comment preceding the call to wait_woken()

		 * in cmtp_session().

		 */

		wake_up_interruptible(sk_sleep(session->sock->sk));

	} else

		err = -ENOENT;

net/bluetooth/hidp/core.c

+8 −5
Original line number Diff line number Diff line
@@ -1074,6 +1074,10 @@ static int hidp_session_start_sync(struct hidp_session *session) 
static void hidp_session_terminate(struct hidp_session *session)

{

	atomic_inc(&session->terminate);

	/*

	 * See the comment preceding the call to wait_woken()

	 * in hidp_session_run().

	 */

	wake_up_interruptible(&hidp_session_wq);

}
@@ -1193,8 +1197,6 @@ static void hidp_session_run(struct hidp_session *session) 
		 *    thread is woken up by ->sk_state_changed().

		 */



		/* Ensure session->terminate is updated */

		smp_mb__before_atomic();

		if (atomic_read(&session->terminate))

			break;
@@ -1228,14 +1230,15 @@ static void hidp_session_run(struct hidp_session *session) 
		hidp_process_transmit(session, &session->ctrl_transmit,

				      session->ctrl_sock);



		/*

		 * wait_woken() performs the necessary memory barriers

		 * for us; see the header comment for this primitive.

		 */

		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);

	}

	remove_wait_queue(&hidp_session_wq, &wait);



	atomic_inc(&session->terminate);



	/* Ensure session->terminate is updated */

	smp_mb__after_atomic();

}



static int hidp_session_wake_function(wait_queue_entry_t *wait,