static void snd_echo_midi_output_trigger(
struct snd_rawmidi_substream *substream, int up);
static int midi_service_irq(struct echoaudio *chip);
static void snd_echo_midi_output_trigger(
struct snd_rawmidi_substream *substream, int up);
static int midi_service_irq(struct echoaudio *chip);