diff options
Diffstat (limited to 'net/bluetooth/hci_request.c')
-rw-r--r-- | net/bluetooth/hci_request.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c index eba83a2..e49f682 100644 --- a/net/bluetooth/hci_request.c +++ b/net/bluetooth/hci_request.c @@ -395,3 +395,99 @@ int hci_update_random_address(struct hci_request *req, bool require_privacy, return 0; } + +/* This function controls the background scanning based on hdev->pend_le_conns + * list. If there are pending LE connection we start the background scanning, + * otherwise we stop it. + * + * This function requires the caller holds hdev->lock. + */ +void __hci_update_background_scan(struct hci_request *req) +{ + struct hci_dev *hdev = req->hdev; + struct hci_conn *conn; + + if (!test_bit(HCI_UP, &hdev->flags) || + test_bit(HCI_INIT, &hdev->flags) || + test_bit(HCI_SETUP, &hdev->dev_flags) || + test_bit(HCI_CONFIG, &hdev->dev_flags) || + test_bit(HCI_AUTO_OFF, &hdev->dev_flags) || + test_bit(HCI_UNREGISTER, &hdev->dev_flags)) + return; + + /* No point in doing scanning if LE support hasn't been enabled */ + if (!test_bit(HCI_LE_ENABLED, &hdev->dev_flags)) + return; + + /* If discovery is active don't interfere with it */ + if (hdev->discovery.state != DISCOVERY_STOPPED) + return; + + /* Reset RSSI and UUID filters when starting background scanning + * since these filters are meant for service discovery only. + * + * The Start Discovery and Start Service Discovery operations + * ensure to set proper values for RSSI threshold and UUID + * filter list. So it is safe to just reset them here. + */ + hci_discovery_filter_clear(hdev); + + if (list_empty(&hdev->pend_le_conns) && + list_empty(&hdev->pend_le_reports)) { + /* If there is no pending LE connections or devices + * to be scanned for, we should stop the background + * scanning. + */ + + /* If controller is not scanning we are done. */ + if (!test_bit(HCI_LE_SCAN, &hdev->dev_flags)) + return; + + hci_req_add_le_scan_disable(req); + + BT_DBG("%s stopping background scanning", hdev->name); + } else { + /* If there is at least one pending LE connection, we should + * keep the background scan running. + */ + + /* If controller is connecting, we should not start scanning + * since some controllers are not able to scan and connect at + * the same time. + */ + conn = hci_conn_hash_lookup_state(hdev, LE_LINK, BT_CONNECT); + if (conn) + return; + + /* If controller is currently scanning, we stop it to ensure we + * don't miss any advertising (due to duplicates filter). + */ + if (test_bit(HCI_LE_SCAN, &hdev->dev_flags)) + hci_req_add_le_scan_disable(req); + + hci_req_add_le_passive_scan(req); + + BT_DBG("%s starting background scanning", hdev->name); + } +} + +static void update_background_scan_complete(struct hci_dev *hdev, u8 status) +{ + if (status) + BT_DBG("HCI request failed to update background scanning: " + "status 0x%2.2x", status); +} + +void hci_update_background_scan(struct hci_dev *hdev) +{ + int err; + struct hci_request req; + + hci_req_init(&req, hdev); + + __hci_update_background_scan(&req); + + err = hci_req_run(&req, update_background_scan_complete); + if (err && err != -ENODATA) + BT_ERR("Failed to run HCI request: err %d", err); +} |