snd_xferi         546 include/uapi/sound/asound.h #define SNDRV_PCM_IOCTL_WRITEI_FRAMES	_IOW('A', 0x50, struct snd_xferi)
snd_xferi         547 include/uapi/sound/asound.h #define SNDRV_PCM_IOCTL_READI_FRAMES	_IOR('A', 0x51, struct snd_xferi)