Bluetooth: Use continuous scanning when creating LE connections

All LE connections are now triggered through a preceding passive scan
and waiting for a connectable advertising report. This means we've got
the best possible guarantee that the device is within range and should
be able to request the controller to perform continuous scanning. This
way we minimize the risk that we miss out on any advertising packets.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org # 4.3+

net/bluetooth/hci_conn.c

@@ -726,8 +726,12 @@ static void hci_req_add_le_create_conn(struct hci_request *req,
 	if (hci_update_random_address(req, false, &own_addr_type))
 		return;
 
+	/* Set window to be the same value as the interval to enable
+	 * continuous scanning.
+	 */
 	cp.scan_interval = cpu_to_le16(hdev->le_scan_interval);
-	cp.scan_window = cpu_to_le16(hdev->le_scan_window);
+	cp.scan_window = cp.scan_interval;
+
 	bacpy(&cp.peer_addr, &conn->dst);
 	cp.peer_addr_type = conn->dst_type;
 	cp.own_address_type = own_addr_type;