SNDRV_PCM_SUBFORMAT_STD 243 include/sound/asound.h #define SNDRV_PCM_SUBFORMAT_LAST SNDRV_PCM_SUBFORMAT_STD SNDRV_PCM_SUBFORMAT_STD 1938 sound/core/pcm_native.c err = snd_pcm_hw_constraint_mask(runtime, SNDRV_PCM_HW_PARAM_SUBFORMAT, 1 << SNDRV_PCM_SUBFORMAT_STD);