snd_xfern 442 include/sound/asound.h struct snd_xfern { snd_xfern 480 include/sound/asound.h SNDRV_PCM_IOCTL_WRITEN_FRAMES = _IOW('A', 0x52, struct snd_xfern), snd_xfern 481 include/sound/asound.h SNDRV_PCM_IOCTL_READN_FRAMES = _IOR('A', 0x53, struct snd_xfern),