Bluetooth: Track received events in hdev

This patch adds tracking of received HCI events to the hci_dev struct.
This is necessary so that a subsequent patch can implement a function
for sending a single command synchronously and returning the resulting
command complete parameters in the function return value.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 7e7fbca..ed0efb7 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3699,6 +3699,18 @@
 	struct hci_event_hdr *hdr = (void *) skb->data;
 	__u8 event = hdr->evt;
 
+	hci_dev_lock(hdev);
+
+	/* Received events are (currently) only needed when a request is
+	 * ongoing so avoid unnecessary memory allocation.
+	 */
+	if (hdev->req_status == HCI_REQ_PEND) {
+		kfree_skb(hdev->recv_evt);
+		hdev->recv_evt = skb_clone(skb, GFP_KERNEL);
+	}
+
+	hci_dev_unlock(hdev);
+
 	skb_pull(skb, HCI_EVENT_HDR_SIZE);
 
 	switch (event) {