device_set_flags
device_set_flags(child, t);
device_set_flags(dev, 1);
device_set_flags(sc->sc_ports[i].dev,
device_set_flags(child, f);
#define SET_FLAG(dev, bit) device_set_flags(dev, device_get_flags(dev) | (bit))
#define CLR_FLAG(dev, bit) device_set_flags(dev, device_get_flags(dev) & ~(bit))
void device_set_flags(device_t dev, u_int32_t flags);