Re: [PATCH] Bluetooth: Move shutdown callback before flushing tx and rx queue
From: Hsin-Yi Wang <hidden>
Date: 2021-08-10 04:11:07
Also in:
linux-bluetooth, lkml
On Tue, Aug 10, 2021 at 1:44 AM Kai-Heng Feng [off-list ref] wrote:
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>Hello, Sorry for confusion, but the version I tested is this one: https://lkml.org/lkml/2021/8/4/486 (shutdown is prior to the test_and_clear HCI_UP) I tested this version and still see the error I've seen before.
quoted hunk ↗ jump to hunk
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> --- net/bluetooth/hci_core.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index cb2e9e513907..8da04c899197 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c@@ -1735,6 +1735,14 @@ int hci_dev_do_close(struct hci_dev *hdev) hci_leds_update_powered(hdev, false); + 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); + } + /* Flush RX and TX works */ flush_work(&hdev->tx_work); flush_work(&hdev->rx_work);@@ -1798,14 +1806,6 @@ int hci_dev_do_close(struct hci_dev *hdev) clear_bit(HCI_INIT, &hdev->flags); } - 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); - } - /* flush cmd work */ flush_work(&hdev->cmd_work); --2.31.1