Bluetooth: Add hci_request support for hci_update_background_scan

[cascardo/linux.git] / net / bluetooth / hci_request.c

diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index eba83a2..e49f682 100644 (file)
--- 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);
+}