sndbuf_getkq
struct kqinfo *sndbuf_getkq(struct snd_dbuf *b);
if (SLIST_FIRST(&sndbuf_getkq(bs)->ki_note) && chn_polltrigger(c)) {
KNOTE(&sndbuf_getkq(bs)->ki_note, 0);
klist = &sndbuf_getkq(bs)->ki_note;
klist = &sndbuf_getkq(bs)->ki_note;