status = snd_sbmixer_read(chip, SB_DSP4_IRQSTATUS);
spin_unlock(&chip->mixer_lock);
if ((status & SB_IRQTYPE_MPUIN) && chip->rmidi_callback)
status = snd_sbmixer_read(chip, SB_DSP4_IRQSTATUS);
spin_unlock(&chip->mixer_lock);
if ((status & SB_IRQTYPE_MPUIN) && chip->rmidi_callback)