SACOM_RING_SIZE
scc = cc = SACOM_RING_SIZE - sc->sc_rbavail;
get -= SACOM_RING_SIZE << 1;
sc->sc_rbuf = kmem_alloc(SACOM_RING_SIZE << 1, KM_SLEEP);
sc->sc_rbavail = SACOM_RING_SIZE;
sc->sc_ebuf = sc->sc_rbuf + (SACOM_RING_SIZE << 1);
kmem_free(sc->sc_rbuf, SACOM_RING_SIZE << 1);
sc->sc_rbavail = SACOM_RING_SIZE;