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 <[email protected]>
Signed-off-by: Sonny Sasaka <[email protected]>
---
net/bluetooth/hci_request.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index d7ee11ef70d3e..8ace5d34b01ef 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -3252,6 +3252,7 @@ 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, false);
}
--
2.29.2
This is automated email and please do not reply to this email!
Dear submitter,
Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=448487
---Test result---
##############################
Test: CheckPatch - PASS
##############################
Test: CheckGitLint - PASS
##############################
Test: CheckBuildK - PASS
##############################
Test: CheckTestRunner: Setup - PASS
##############################
Test: CheckTestRunner: l2cap-tester - PASS
Total: 40, Passed: 34 (85.0%), Failed: 0, Not Run: 6
##############################
Test: CheckTestRunner: bnep-tester - PASS
Total: 1, Passed: 1 (100.0%), Failed: 0, Not Run: 0
##############################
Test: CheckTestRunner: mgmt-tester - FAIL
Total: 416, Passed: 397 (95.4%), Failed: 3, Not Run: 16
##############################
Test: CheckTestRunner: rfcomm-tester - PASS
Total: 9, Passed: 9 (100.0%), Failed: 0, Not Run: 0
##############################
Test: CheckTestRunner: sco-tester - PASS
Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0
##############################
Test: CheckTestRunner: smp-tester - PASS
Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0
##############################
Test: CheckTestRunner: userchan-tester - PASS
Total: 3, Passed: 3 (100.0%), Failed: 0, Not Run: 0
---
Regards,
Linux Bluetooth
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 <[email protected]>
> Signed-off-by: Sonny Sasaka <[email protected]>
>
> ---
> net/bluetooth/hci_request.c | 1 +
> 1 file changed, 1 insertion(+)
patch has been applied to bluetooth-next tree.
Regards
Marcel