struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
struct dummy_model *model = dummy->model;
struct snd_pcm_runtime *runtime = substream->runtime;
struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
struct dummy_model *model = dummy->model;
struct snd_pcm_runtime *runtime = substream->runtime;