GMAC_OP_MODE
mode = dwge_read(sc, GMAC_OP_MODE);
dwge_write(sc, GMAC_OP_MODE, mode | GMAC_OP_MODE_ST | GMAC_OP_MODE_SR);
dmactrl = dwge_read(sc, GMAC_OP_MODE);
dwge_write(sc, GMAC_OP_MODE, dmactrl);
dmactrl = dwge_read(sc, GMAC_OP_MODE);
dwge_write(sc, GMAC_OP_MODE, dmactrl);
mode = dwge_read(sc, GMAC_OP_MODE);
dwge_write(sc, GMAC_OP_MODE, mode & ~GMAC_OP_MODE_SR);
dwge_write(sc, GMAC_OP_MODE, mode);