Show modal while another controller method is running and shows its elements

Hello, good morning, I have the following problem. I have a controller reg_calls_controller.php which has its function index and load the view reg_calls_view.php , in the html I have several things in between button that calls to the following JavaScript function .

function msj_cargando() {
            $('#modalLoad').modal('show');

            $.ajax({
            url : "<?php echo base_url('index.php/reg_calls_controller/todas_calls/')?>",
            type: "POST",
            dataType: "JSON",
            success: function(data) {
                console.log(data);
                //alert(data);
                $('#modalLoad').modal('hide');  
            },
            error: function (jqXHR, textStatus, errorThrown) {
                alert(textStatus);
                $('#modalLoad').modal('hide');
                swal({
                  title: "Error!",
                  text: "La conexion no fue exitosa!",
                  icon: "error",
                  button: true,
                  dangerMode: false,
                });
            }
        });

        }

In the JS first I show the following modal that is in reg_calls_view.php and I use it as a loading.

<div id="modalLoad" class="modal fade" role="dialog">
	  <div class="modal-dialog">
	    <!-- Modal content-->
	    <div class="modal-content">
	      <div class="modal-body text-center"">
	        <i class="fa fa-spinner fa-spin fa-5x"></i>
	        <p><h3>Cargando...</h3></p>
	      </div>
	      <div class="modal-footer">
	        <button type="button" class="btn btn-danger" data-dismiss="modal">Cancelar</button>
	      </div>
	    </div>

	  </div>
	</div>

But what I try to do is to show that modal while I call the function all_calls which is the same in reg_calls_controller.php and this function at the same time make a query the results send them all_calls_view.php and finally the modality is closed.

public function todas_calls() {

  $sess_array = array(
    'id_user' => $this->session->userdata['sess_data']['id_user'],
    'username' => $this->session->userdata['sess_data']['username']
  );

  $data = array();
  $data['sess_data'] = $sess_array;

  $data['todas_calls']  = $this->reg_calls_model->todas_calls();

  $data['menu_higher'] = $this->load->view('elementos/menu_higher_view.php', $data, TRUE);
  $data['menu_left'] = $this->load->view('elementos/menu_left_view.php', '', TRUE);

  echo json_encode($data);

  $this->load->view("todas_calls_view.php", $data);

}

I hope you can help me.