RTSX_HDBCTLR
WRITE4(sc, RTSX_HDBCTLR, dmaflags);
WRITE4(sc, RTSX_HDBCTLR, RTSX_STOP_DMA);
sc->regs4[3] = READ4(sc, RTSX_HDBCTLR);
WRITE4(sc, RTSX_HDBCTLR, sc->regs4[3]);