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

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 <redacted>
Tested-by: Hsin-Yi Wang <redacted>
Cc: Guenter Roeck <linux@roeck-us.net>
Fixes: 0ea9fd001a14 ("Bluetooth: Shutdown controller after workqueues are flushed or cancelled")
Signed-off-by: Kai-Heng Feng <redacted>
---
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