DWC3_GCTL
reg = DWC3_READ(sc, DWC3_GCTL);
gctl = DWC3_READ(sc, DWC3_GCTL);
DWC3_WRITE(sc, DWC3_GCTL, gctl);
DWC3_WRITE(sc, DWC3_GCTL, gctl);
reg = DWC3_READ(sc, DWC3_GCTL);
DWC3_WRITE(sc, DWC3_GCTL, reg);