ioc_play_msf
struct ioc_play_msf tt_msf;
int mcd_playmsf(struct mcd_softc *, struct ioc_play_msf *);
mcd_playmsf(struct mcd_softc *sc, struct ioc_play_msf *p)
struct ioc_play_msf *args = addr;
#define CDIOCPLAYMSF _IOW('c', 25, struct ioc_play_msf)
struct ioc_play_msf a;