Bluetooth: optimize barrier usage for Rmw atomics
Use smp_mb__before_atomic() instead of smp_mb() and avoid the
unnecessary barrier for non LL/SC architectures, such as x86.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/hidp/core.c b/net/bluetooth/hidp/core.c
index bef84b9..3b4fa27 100644
--- a/net/bluetooth/hidp/core.c
+++ b/net/bluetooth/hidp/core.c
@@ -1279,7 +1279,7 @@
add_wait_queue(sk_sleep(session->intr_sock->sk), &intr_wait);
/* This memory barrier is paired with wq_has_sleeper(). See
* sock_poll_wait() for more information why this is needed. */
- smp_mb();
+ smp_mb__before_atomic();
/* notify synchronous startup that we're ready */
atomic_inc(&session->state);
