static void ahci_cmd_done(IDEDMA *dma)
{
    AHCIDevice *ad = DO_UPCAST(AHCIDevice, dma, dma);

    DPRINTF(ad->port_no, "cmd done\n");

    /* update d2h status */
    ahci_write_fis_d2h(ad);

    if (!ad->check_bh) {
        /* maybe we still have something to process, check later */
        ad->check_bh = qemu_bh_new(ahci_check_cmd_bh, ad);
        qemu_bh_schedule(ad->check_bh);
    }
}

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