SNDCTL_DSP_MAPOUTBUF 690 include/uapi/linux/soundcard.h #define SOUND_PCM_MAPOUTBUF SNDCTL_DSP_MAPOUTBUF SNDCTL_DSP_MAPOUTBUF 2687 sound/core/oss/pcm_oss.c case SNDCTL_DSP_MAPOUTBUF: