[PATCH] Bluetooth: btmtk: remove redundant memory barrier with helper

[PATCH] Bluetooth: btmtk: remove redundant memory barrier with helper

[Arnaud Bonnet]

The test_and_clear_bit() call works as a full memory barrier, thus it is
not required to emit a barrier using smp_mb__after_atomic() before
wake_up_bit().

Replace the whole sequence with test_and_clear_wake_up_bit(), which was
introduced later in commit 52d633def56c ("sched: Add
test_and_clear_wake_up_bit() and atomic_dec_and_wake_up()") as a wrapper
for the correct sequence.

Signed-off-by: Arnaud Bonnet <abo@medichon.fr>
---
Tested by building and manually checking generated assembly on x86, arm64
and riscv64.

 drivers/bluetooth/btmtk.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/bluetooth/btmtk.c b/drivers/bluetooth/btmtk.c
index 75483d8230e1..a620e24b6c17 100644
--- a/drivers/bluetooth/btmtk.c
+++ b/drivers/bluetooth/btmtk.c
@@ -607,13 +607,7 @@ static void btmtk_usb_wmt_recv(struct urb *urb)
 			return;
 		}
 
-		if (test_and_clear_bit(BTMTK_TX_WAIT_VND_EVT,
-				       &data->flags)) {
-			/* Barrier to sync with other CPUs */
-			smp_mb__after_atomic();
-			wake_up_bit(&data->flags,
-				    BTMTK_TX_WAIT_VND_EVT);
-		}
+		test_and_clear_wake_up_bit(BTMTK_TX_WAIT_VND_EVT, &data->flags);
 		kfree(urb->setup_packet);
 		return;
 	} else if (urb->status == -ENOENT) {
-- 
2.53.0