Bluetooth: Add stubs for synchronous HCI request functionality

Prepare hci_request.c to have code for doing synchronous HCI requests,
such as LE scanning or advertising changes. The necessary work
callbacks will be set up in hci_request_setup() and cleaned up in
hci_request_cancel_all(). The former is used when an HCI device get
registered, and the latter each time it is powered off (or
unregistered).

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/hci_core.c

@@ -1609,6 +1609,8 @@ int hci_dev_do_close(struct hci_dev *hdev)
 
 	hci_req_sync_unlock(hdev);
 
+	hci_request_cancel_all(hdev);
+
 	hci_dev_put(hdev);
 	return 0;
 }
@@ -3161,6 +3163,8 @@ struct hci_dev *hci_alloc_dev(void)
 
 	INIT_DELAYED_WORK(&hdev->cmd_timer, hci_cmd_timeout);
 
+	hci_request_setup(hdev);
+
 	hci_init_sysfs(hdev);
 	discovery_init(hdev);
 

net/bluetooth/hci_request.c

@@ -845,3 +845,11 @@ int hci_abort_conn(struct hci_conn *conn, u8 reason)
 
 	return 0;
 }
+
+void hci_request_setup(struct hci_dev *hdev)
+{
+}
+
+void hci_request_cancel_all(struct hci_dev *hdev)
+{
+}

net/bluetooth/hci_request.h

@@ -70,3 +70,6 @@ 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);
+
+void hci_request_setup(struct hci_dev *hdev);
+void hci_request_cancel_all(struct hci_dev *hdev);