[PATCH 5.13 191/300] Bluetooth: Move shutdown callback before flushing tx and rx queue

Greg Kroah-Hartman
2021-09-13T14:09:28Z

From: Kai-Heng Feng <kai.heng.feng@canonical.com>

[ Upstream commit 0ea53674d07fb6db2dd7a7ec2fdc85a12eb246c2 ]

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>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/bluetooth/hci_core.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index ee59d1c7f1f6..7154af1fad81 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1734,6 +1734,14 @@ int hci_dev_do_close(struct hci_dev *hdev)
hci_request_cancel_all(hdev);
hci_req_sync_lock(hdev);

+ if (!hci_dev_test_flag(hdev, HCI_UNREGISTER) &&
+ !hci_dev_test_flag(hdev, HCI_USER_CHANNEL) &&
+ test_bit(HCI_UP, &hdev->flags)) {
+ /* Execute vendor specific shutdown routine */
+ if (hdev->shutdown)
+ hdev->shutdown(hdev);
+ }
+
if (!test_and_clear_bit(HCI_UP, &hdev->flags)) {
cancel_delayed_work_sync(&hdev->cmd_timer);
hci_req_sync_unlock(hdev);
--
2.30.2