PREF_UNIT_PUT_IDX
sky2_write16(hw, Y2_QADDR(q, PREF_UNIT_PUT_IDX), idx);
(unsigned) sky2_read16(hw, Y2_QADDR(q, PREF_UNIT_PUT_IDX)));
sky2_read16(hw, Y2_QADDR(rxqaddr[port], PREF_UNIT_PUT_IDX)),