RT2661_MGT_RING_COUNT
sc->mgtq.cur = (sc->mgtq.cur + 1) % RT2661_MGT_RING_COUNT;
if (sc->mgtq.queued >= RT2661_MGT_RING_COUNT) {
RT2661_MGT_RING_COUNT);
error = rt2661_alloc_tx_ring(sc, &sc->mgtq, RT2661_MGT_RING_COUNT);