Bluetooth: Add hci_request support for hci_update_background_scan
Many places using hci_update_background_scan() try to synchronize
whatever they're doing with the help of hci_request callbacks. However,
since the hci_update_background_scan() function hasn't so far accepted a
hci_request pointer any commands triggered by it have been left out by
the synchronization. This patch modifies the API in a similar way as was
done for hci_update_page_scan, i.e. there's a variant that takes a
hci_request and another one that takes a hci_dev.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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 @@
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);
+}