Hi Kai-Heng,
> Commit 0ea9fd001a14 ("Bluetooth: Shutdown controller after workqueues
> are flushed or cancelled") introduced a regression that makes mtkbtsdio
> driver stops working:
> [ 36.593956] Bluetooth: hci0: Firmware already downloaded
> [ 46.814613] Bluetooth: hci0: Execution of wmt command timed out
> [ 46.814619] Bluetooth: hci0: Failed to send wmt func ctrl (-110)
>
> The shutdown callback depends on the result of hdev->rx_work, so we
> should call it before flushing rx_work:
> -> btmtksdio_shutdown()
> -> mtk_hci_wmt_sync()
> -> __hci_cmd_send()
> -> wait for BTMTKSDIO_TX_WAIT_VND_EVT gets cleared
>
> -> btmtksdio_recv_event()
> -> hci_recv_frame()
> -> queue_work(hdev->workqueue, &hdev->rx_work)
> -> clears BTMTKSDIO_TX_WAIT_VND_EVT
>
> So move the shutdown callback before flushing TX/RX queue to resolve the
> issue.
>
> Reported-and-tested-by: Mattijs Korpershoek <mkorpershoek@xxxxxxxxxxxx>
> Tested-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
> Fixes: 0ea9fd001a14 ("Bluetooth: Shutdown controller after workqueues are flushed or cancelled")
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> ---
> v2:
> Move the shutdown callback before clearing HCI_UP, otherwise 1)
> shutdown callback won't be called and 2) other routines that depend on
> HCI_UP won't work.
>
> net/bluetooth/hci_core.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
patch has been applied to bluetooth-next tree.
Regards
Marcel
