SNDRV_PCM_IOCTL_HW_FREE 496 sound/core/pcm_compat.c case SNDRV_PCM_IOCTL_HW_FREE: SNDRV_PCM_IOCTL_HW_FREE 2514 sound/core/pcm_native.c case SNDRV_PCM_IOCTL_HW_FREE: