AR_PHY_TX_PWRCTRL9
reg = AR_READ(sc, AR_PHY_TX_PWRCTRL9);
AR_WRITE(sc, AR_PHY_TX_PWRCTRL9, reg);
AR_SETBITS(sc, AR_PHY_TX_PWRCTRL9, AR_PHY_TX_PWRCTRL9_RES_DC_REMOVAL);