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: Andrea Parri <andrea.parri@xxxxxxxxxxxxxxxxxxxx>
---
net/bluetooth/bnep/core.c | 7 ++++---
net/bluetooth/cmtp/core.c | 14 ++++++++------
net/bluetooth/hidp/core.c | 13 ++++++++-----
3 files changed, 20 insertions(+), 14 deletions(-)
diff --git a/net/bluetooth/bnep/core.c b/net/bluetooth/bnep/core.c
index 7b3965861013c..43c284158f63e 100644
--- a/net/bluetooth/bnep/core.c
+++ b/net/bluetooth/bnep/core.c
@@ -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);
diff --git a/net/bluetooth/cmtp/core.c b/net/bluetooth/cmtp/core.c
index 7f26a5a19ff6d..07cfa3249f83a 100644
--- a/net/bluetooth/cmtp/core.c
+++ b/net/bluetooth/cmtp/core.c
@@ -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;
diff --git a/net/bluetooth/hidp/core.c b/net/bluetooth/hidp/core.c
index 1036e4fa1ea28..e621551712f59 100644
--- a/net/bluetooth/hidp/core.c
+++ b/net/bluetooth/hidp/core.c
@@ -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,
--
2.7.4
