static int mixer_ctl_procunit_put(struct snd_kcontrol *kcontrol,
				  struct snd_ctl_elem_value *ucontrol)
{
	struct usb_mixer_elem_info *cval = kcontrol->private_data;
	int val, oval, err;

	err = get_cur_ctl_value(cval, cval->control << 8, &oval);
	if (err < 0)
		return filter_error(cval, err);
	val = ucontrol->value.integer.value[0];
	val = get_abs_value(cval, val);
	if (val != oval) {
		set_cur_ctl_value(cval, cval->control << 8, val);
		return 1;
	}
	return 0;
}
static int mixer_ctl_procunit_put(struct snd_kcontrol *kcontrol,
				  struct snd_ctl_elem_value *ucontrol)
{
	struct usb_mixer_elem_info *cval = kcontrol->private_data;
	int val, oval, err;

	err = get_cur_ctl_value(cval, cval->control << 8, &oval);
	if (err < 0)
		return filter_error(cval, err);
	val = ucontrol->value.integer.value[0];
	val = get_abs_value(cval, val);
	if (val != oval) {
		set_cur_ctl_value(cval, cval->control << 8, val);
		return 1;
	}
	return 0;
}