void usb_ehci_realize(EHCIState *s, DeviceState *dev, Error **errp)
{
    int i;

    if (s->portnr > NB_PORTS) {
        error_setg(errp, "Too many ports! Max. port number is %d.",
                   NB_PORTS);
        return;
    }

    usb_bus_new(&s->bus, sizeof(s->bus), s->companion_enable ?
                &ehci_bus_ops_companion : &ehci_bus_ops_standalone, dev);
    for (i = 0; i < s->portnr; i++) {
        usb_register_port(&s->bus, &s->ports[i], s, i, &ehci_port_ops,
                          USB_SPEED_MASK_HIGH);
        s->ports[i].dev = 0;
    }

    s->frame_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, ehci_frame_timer, s);
    s->async_bh = qemu_bh_new(ehci_frame_timer, s);
    s->device = dev;

    s->vmstate = qemu_add_vm_change_state_handler(usb_ehci_vm_state_change, s);
}

The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.