struct snd_dg00x *dg00x = substream->rmidi->private_data;
        int err;
 
+       /* This port is for asynchronous transaction. */
+       if (substream->number == 0)
+               return 0;
+
        err = snd_dg00x_stream_lock_try(dg00x);
        if (err < 0)
                return err;
 {
        struct snd_dg00x *dg00x = substream->rmidi->private_data;
 
+       /* This port is for asynchronous transaction. */
+       if (substream->number == 0)
+               return 0;
+
        mutex_lock(&dg00x->mutex);
        dg00x->substreams_counter--;
        snd_dg00x_stream_stop_duplex(dg00x);
 
        spin_lock_irqsave(&dg00x->lock, flags);
 
-       if (up)
-               amdtp_dot_midi_trigger(&dg00x->tx_stream,
-                                      substrm->number, substrm);
-       else
-               amdtp_dot_midi_trigger(&dg00x->tx_stream,
-                                      substrm->number, NULL);
+       /* This port is for asynchronous transaction. */
+       if (substrm->number == 0) {
+               if (up)
+                       dg00x->in_control = substrm;
+               else
+                       dg00x->in_control = NULL;
+       } else {
+               if (up)
+                       amdtp_dot_midi_trigger(&dg00x->tx_stream,
+                                              substrm->number - 1, substrm);
+               else
+                       amdtp_dot_midi_trigger(&dg00x->tx_stream,
+                                              substrm->number - 1, NULL);
+       }
 
        spin_unlock_irqrestore(&dg00x->lock, flags);
 }
 
        spin_lock_irqsave(&dg00x->lock, flags);
 
-       if (up)
-               amdtp_dot_midi_trigger(&dg00x->rx_stream,
-                                      substrm->number, substrm);
-       else
-               amdtp_dot_midi_trigger(&dg00x->rx_stream,
-                                      substrm->number, NULL);
+       /* This port is for asynchronous transaction. */
+       if (substrm->number == 0) {
+               if (up)
+                       snd_fw_async_midi_port_run(&dg00x->out_control,
+                                                  substrm);
+       } else {
+               if (up)
+                       amdtp_dot_midi_trigger(&dg00x->rx_stream,
+                                              substrm->number - 1, substrm);
+               else
+                       amdtp_dot_midi_trigger(&dg00x->rx_stream,
+                                              substrm->number - 1, NULL);
+       }
 
        spin_unlock_irqrestore(&dg00x->lock, flags);
 }
        struct snd_rawmidi_substream *subs;
 
        list_for_each_entry(subs, &str->substreams, list) {
-               snprintf(subs->name, sizeof(subs->name),
-                        "%s MIDI %d",
-                        dg00x->card->shortname, subs->number + 1);
+               if (subs->number > 0)
+                       snprintf(subs->name, sizeof(subs->name),
+                                "%s MIDI %d",
+                                dg00x->card->shortname, subs->number);
+               else
+                       /* This port is for asynchronous transaction. */
+                       snprintf(subs->name, sizeof(subs->name),
+                                "%s control",
+                                dg00x->card->shortname);
        }
 }
 
        int err;
 
        err = snd_rawmidi_new(dg00x->card, dg00x->card->driver, 0,
-                             DOT_MIDI_OUT_PORTS, DOT_MIDI_IN_PORTS, &rmidi);
+                       DOT_MIDI_OUT_PORTS + 1, DOT_MIDI_IN_PORTS + 1, &rmidi);
        if (err < 0)
                return err;