[Bluetooth] Support concurrent connect requests

Most Bluetooth chips don't support concurrent connect requests, because
this would involve a multiple baseband page with only one radio. In the
case an upper layer like L2CAP requests a concurrent connect these chips
return the error "Command Disallowed" for the second request. If this
happens it the responsibility of the Bluetooth core to queue the request
and try again after the previous connect attempt has been completed.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index d43d0c8..65f0948 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -414,9 +414,12 @@
 
 	if (status) {
 		if (conn && conn->state == BT_CONNECT) {
-			conn->state = BT_CLOSED;
-			hci_proto_connect_cfm(conn, status);
-			hci_conn_del(conn);
+			if (status != 0x0c || conn->attempt > 2) {
+				conn->state = BT_CLOSED;
+				hci_proto_connect_cfm(conn, status);
+				hci_conn_del(conn);
+			} else
+				conn->state = BT_CONNECT2;
 		}
 	} else {
 		if (!conn) {
@@ -728,7 +731,7 @@
 static inline void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	struct hci_ev_conn_complete *ev = (struct hci_ev_conn_complete *) skb->data;
-	struct hci_conn *conn;
+	struct hci_conn *conn, *pend;
 
 	BT_DBG("%s", hdev->name);
 
@@ -801,6 +804,10 @@
 	if (ev->status)
 		hci_conn_del(conn);
 
+	pend = hci_conn_hash_lookup_state(hdev, ACL_LINK, BT_CONNECT2);
+	if (pend)
+		hci_acl_connect(pend);
+
 	hci_dev_unlock(hdev);
 }