Re: [PATCH v2] Bluetooth: Move shutdown callback before flushing tx and rx queue

[Marcel Holtmann <marcel@holtmann.org>]

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@baylibre.com>
> Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Fixes: 0ea9fd001a14 ("Bluetooth: Shutdown controller after workqueues are flushed or cancelled")
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
> 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