static int req_run(struct hci_request *req, hci_req_complete_t complete,
		   hci_req_complete_skb_t complete_skb)
{
	struct hci_dev *hdev = req->hdev;
	struct sk_buff *skb;
	unsigned long flags;

	bt_dev_dbg(hdev, "length %u", skb_queue_len(&req->cmd_q));

	/* If an error occurred during request building, remove all HCI
	 * commands queued on the HCI request queue.
	 */
	if (req->err) {
		skb_queue_purge(&req->cmd_q);
		return req->err;
	}

	/* Do not allow empty requests */
	if (skb_queue_empty(&req->cmd_q))
		return -ENODATA;

	skb = skb_peek_tail(&req->cmd_q);
	if (complete) {
		bt_cb(skb)->hci.req_complete = complete;
	} else if (complete_skb) {
		bt_cb(skb)->hci.req_complete_skb = complete_skb;
		bt_cb(skb)->hci.req_flags |= HCI_REQ_SKB;
	}

	spin_lock_irqsave(&hdev->cmd_q.lock, flags);
	skb_queue_splice_tail(&req->cmd_q, &hdev->cmd_q);
	spin_unlock_irqrestore(&hdev->cmd_q.lock, flags);

	queue_work(hdev->workqueue, &hdev->cmd_work);

	return 0;
}