static int constrain_interval_params(struct snd_pcm_substream *substream,
				     struct snd_pcm_hw_params *params)
{
	struct snd_pcm_hw_constraints *constrs =
					&substream->runtime->hw_constraints;
	struct snd_interval *i;
	unsigned int k;
	struct snd_interval old_interval;
	int changed;

	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++) {
		i = hw_param_interval(params, k);
		if (snd_interval_empty(i))
			return -EINVAL;

		/* This parameter is not requested to change by a caller. */
		if (!(params->rmask & PARAM_MASK_BIT(k)))
			continue;

		if (trace_hw_interval_param_enabled())
			old_interval = *i;

		changed = snd_interval_refine(i, constrs_interval(constrs, k));
		if (changed < 0)
			return changed;
		if (changed == 0)
			continue;

		/* Set corresponding flag so that the caller gets it. */
		trace_hw_interval_param(substream, k, 0, &old_interval, i);
		params->cmask |= PARAM_MASK_BIT(k);
	}

	return 0;
}
static int constrain_interval_params(struct snd_pcm_substream *substream,
				     struct snd_pcm_hw_params *params)
{
	struct snd_pcm_hw_constraints *constrs =
					&substream->runtime->hw_constraints;
	struct snd_interval *i;
	unsigned int k;
	struct snd_interval old_interval;
	int changed;

	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++) {
		i = hw_param_interval(params, k);
		if (snd_interval_empty(i))
			return -EINVAL;

		 
		if (!(params->rmask & PARAM_MASK_BIT(k)))
			continue;

		if (trace_hw_interval_param_enabled())
			old_interval = *i;

		changed = snd_interval_refine(i, constrs_interval(constrs, k));
		if (changed < 0)
			return changed;
		if (changed == 0)
			continue;

		 
		trace_hw_interval_param(substream, k, 0, &old_interval, i);
		params->cmask |= PARAM_MASK_BIT(k);
	}

	return 0;
}