On Thu, Aug 13, 2020 at 01:40:50PM +0200, [email protected] wrote:
> On Thu, Aug 13, 2020 at 08:31:15AM +0100, Christoph Hellwig wrote:
> > On Thu, Aug 13, 2020 at 10:44:38AM +0800, Jacob Wen wrote:
> > > wake_up_bit() uses waitqueue_active() that needs the explicit smp_mb().
> >
> > Sounds like the barrier should go into wake_up_bit then..
>
> Oh, thanks for reminding me..
>
> https://lkml.kernel.org/r/[email protected]
>
> I'll try and get back to that.
+++ b/drivers/bluetooth/btmtkuart.c
@@ -340,11 +340,8 @@ static int btmtkuart_recv_event(struct hci_dev *hdev,
struct sk_buff *skb)
if (hdr->evt == HCI_EV_VENDOR) {
if (test_and_clear_bit(BTMTKUART_TX_WAIT_VND_EVT,
- &bdev->tx_state)) {
- /* Barrier to sync with other CPUs */
- smp_mb__after_atomic();
+ &bdev->tx_state))
wake_up_bit(&bdev->tx_state, BTMTKUART_TX_WAIT_VND_EVT);
- }
}
return 0;
It'd be nice to be able to write:
if (hdr->evt == HCI_EV_VENDOR)
test_clear_and_wake_up_bit(&bdev->tx_state,
BTMTKUART_TX_WAIT_VND_EVT);
... maybe with a better name.
