WPI_FH_RX_WPTR
WPI_WRITE(sc, WPI_FH_RX_WPTR, hw & ~7);
WPI_WRITE(sc, WPI_FH_RX_WPTR, 0);
WPI_WRITE(sc, WPI_FH_RX_WPTR, (WPI_RX_RING_COUNT - 1) & ~7);