| Message ID | 20210313004435.73331-1-sonnysasaka@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Bluetooth: Cancel le_scan_restart work when stopping discovery | expand |
Hi Sonny, > Not cancelling it has caused a bug where passive background scanning is > disabled out of the blue, preventing BLE keyboards/mice to reconnect. > Here is how it happens: > After hci_req_stop_discovery, there is still le_scan_restart_work > scheduled. Invocation of le_scan_restart_work causes a harmful > le_scan_disable_work to be scheduled. This le_scan_disable_work will > eventually disable passive scanning when the timer fires. > > Sample btmon trace: > > < HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 > Type: Passive (0x00) > Interval: 367.500 msec (0x024c) > Window: 37.500 msec (0x003c) > Own address type: Public (0x00) > Filter policy: Accept all advertisement (0x00) >> HCI Event: Command Complete (0x0e) plen 4 > LE Set Scan Parameters (0x08|0x000b) ncmd 1 > Status: Success (0x00) > < HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 > Scanning: Enabled (0x01) > Filter duplicates: Disabled (0x00) >> HCI Event: Command Complete (0x0e) plen 4 > LE Set Scan Enable (0x08|0x000c) ncmd 2 > Status: Success (0x00) > ... > < HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 > Scanning: Disabled (0x00) > Filter duplicates: Disabled (0x00) >> HCI Event: Command Complete (0x0e) plen 4 > LE Set Scan Enable (0x08|0x000c) ncmd 2 > Status: Success (0x00) > // Background scanning is not working here onwards. > > Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > Signed-off-by: Sonny Sasaka <sonnysasaka@chromium.org> > > --- > net/bluetooth/hci_request.c | 1 + > 1 file changed, 1 insertion(+) I can apply this cleanly to bluetooth-next tree. Please double-check and rebase if it is still needed. Regards Marcel
Hi Marcel, I have just sent a v2 which is rebased on bluetooth-next/master. PTAL. Thanks. On Sat, Mar 13, 2021 at 3:00 AM Marcel Holtmann <marcel@holtmann.org> wrote: > > Hi Sonny, > > > Not cancelling it has caused a bug where passive background scanning is > > disabled out of the blue, preventing BLE keyboards/mice to reconnect. > > Here is how it happens: > > After hci_req_stop_discovery, there is still le_scan_restart_work > > scheduled. Invocation of le_scan_restart_work causes a harmful > > le_scan_disable_work to be scheduled. This le_scan_disable_work will > > eventually disable passive scanning when the timer fires. > > > > Sample btmon trace: > > > > < HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 > > Type: Passive (0x00) > > Interval: 367.500 msec (0x024c) > > Window: 37.500 msec (0x003c) > > Own address type: Public (0x00) > > Filter policy: Accept all advertisement (0x00) > >> HCI Event: Command Complete (0x0e) plen 4 > > LE Set Scan Parameters (0x08|0x000b) ncmd 1 > > Status: Success (0x00) > > < HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 > > Scanning: Enabled (0x01) > > Filter duplicates: Disabled (0x00) > >> HCI Event: Command Complete (0x0e) plen 4 > > LE Set Scan Enable (0x08|0x000c) ncmd 2 > > Status: Success (0x00) > > ... > > < HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 > > Scanning: Disabled (0x00) > > Filter duplicates: Disabled (0x00) > >> HCI Event: Command Complete (0x0e) plen 4 > > LE Set Scan Enable (0x08|0x000c) ncmd 2 > > Status: Success (0x00) > > // Background scanning is not working here onwards. > > > > Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > > Signed-off-by: Sonny Sasaka <sonnysasaka@chromium.org> > > > > --- > > net/bluetooth/hci_request.c | 1 + > > 1 file changed, 1 insertion(+) > > I can apply this cleanly to bluetooth-next tree. Please double-check and rebase if it is still needed. > > Regards > > Marcel >
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c index d7639c4b63104..c64b4a06de708 100644 --- a/net/bluetooth/hci_request.c +++ b/net/bluetooth/hci_request.c @@ -2710,6 +2710,7 @@ bool hci_req_stop_discovery(struct hci_request *req) if (hci_dev_test_flag(hdev, HCI_LE_SCAN)) { cancel_delayed_work(&hdev->le_scan_disable); + cancel_delayed_work(&hdev->le_scan_restart); hci_req_add_le_scan_disable(req); }
Not cancelling it has caused a bug where passive background scanning is disabled out of the blue, preventing BLE keyboards/mice to reconnect. Here is how it happens: After hci_req_stop_discovery, there is still le_scan_restart_work scheduled. Invocation of le_scan_restart_work causes a harmful le_scan_disable_work to be scheduled. This le_scan_disable_work will eventually disable passive scanning when the timer fires. Sample btmon trace: < HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 Type: Passive (0x00) Interval: 367.500 msec (0x024c) Window: 37.500 msec (0x003c) Own address type: Public (0x00) Filter policy: Accept all advertisement (0x00) > HCI Event: Command Complete (0x0e) plen 4 LE Set Scan Parameters (0x08|0x000b) ncmd 1 Status: Success (0x00) < HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 Scanning: Enabled (0x01) Filter duplicates: Disabled (0x00) > HCI Event: Command Complete (0x0e) plen 4 LE Set Scan Enable (0x08|0x000c) ncmd 2 Status: Success (0x00) ... < HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 Scanning: Disabled (0x00) Filter duplicates: Disabled (0x00) > HCI Event: Command Complete (0x0e) plen 4 LE Set Scan Enable (0x08|0x000c) ncmd 2 Status: Success (0x00) // Background scanning is not working here onwards. Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> Signed-off-by: Sonny Sasaka <sonnysasaka@chromium.org> --- net/bluetooth/hci_request.c | 1 + 1 file changed, 1 insertion(+)