usb_needs_explore
usb_needs_explore(bus, 1);
usb_needs_explore(xfer->xroot->bus, 0);
usb_needs_explore(sc->sc_udev->bus, 0);
usb_needs_explore(bus, 1);
usb_needs_explore(bus, 0 /* no probe */ );
usb_needs_explore(udev->bus, 0 /* no probe */ );
usb_needs_explore(udev->bus, 0);
usb_needs_explore(udev->bus, 0);
usb_needs_explore(bus, 0);
void usb_needs_explore(struct usb_bus *bus, uint8_t do_probe);