simid: loaded (softc 0xfffff801173ea498, 120 bytes, mpu 0xfffff80117a89380) - open+write /dev/midi*.* then sysctl hw.simid.detach=1 / kldunload
login: simid[kldunload]: mpu401_uninit() returned 6 (FAILURE - m NOT freed, midi cdev STILL LIVE)  <<< emu_midi_detach IGNORES this and returns 0
simid[kldunload,FIXED]: aborting detach (device stays attached, softc NOT freed, module NOT unloadable)