Bluetooth: Run all background scan updates through req_workqueue

Instead of firing off a simple async request queue all background scan
updates through req_workqueue and use hci_req_sync() there to ensure
that no two updates overlap with each other.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/hci_request.h b/net/bluetooth/hci_request.h
index 9759b71..983e687 100644
--- a/net/bluetooth/hci_request.h
+++ b/net/bluetooth/hci_request.h
@@ -64,12 +64,16 @@
 int hci_update_random_address(struct hci_request *req, bool require_privacy,
 			      u8 *own_addr_type);
 
-void hci_update_background_scan(struct hci_dev *hdev);
 void __hci_update_background_scan(struct hci_request *req);
 
 int hci_abort_conn(struct hci_conn *conn, u8 reason);
 void __hci_abort_conn(struct hci_request *req, struct hci_conn *conn,
 		      u8 reason);
 
+static inline void hci_update_background_scan(struct hci_dev *hdev)
+{
+	queue_work(hdev->req_workqueue, &hdev->bg_scan_update);
+}
+
 void hci_request_setup(struct hci_dev *hdev);
 void hci_request_cancel_all(struct hci_dev *hdev);