Symbol: SOUND_MIXER_WRITE_RECSRC
lib/libmixer/mixer.c
408
if (ioctl(m->fd, SOUND_MIXER_WRITE_RECSRC, &m->recsrc) < 0)
sys/compat/linux/linux_ioctl.c
1886
args->cmd = SETDIR(SOUND_MIXER_WRITE_RECSRC);