PP_RxCTL
writereg(dev, PP_RxCTL, DEF_RX_ACCEPT);
writereg(dev, PP_RxCTL, DEF_RX_ACCEPT | lp->rx_mode);
writereg(dev, PP_RxCTL, DEF_RX_ACCEPT);
writereg(dev, PP_RxCTL, DEF_RX_ACCEPT | lp->rx_mode);