IDPF_CTLQ_DESC
desc = IDPF_CTLQ_DESC(cq, cq->next_to_use);
desc = IDPF_CTLQ_DESC(cq, ntc);
desc = IDPF_CTLQ_DESC(cq, ntp);
desc = IDPF_CTLQ_DESC(cq, ntc);
struct idpf_ctlq_desc *desc = IDPF_CTLQ_DESC(cq, i);