R92C_TRXFF_BNDY
rtwn_pci_write_1(sc, R92C_TRXFF_BNDY, boundary);
rtwn_pci_write_2(sc, R92C_TRXFF_BNDY + 2, dmasize - 1);
urtwn_write_1(sc, R92C_TRXFF_BNDY, boundary);
urtwn_write_2(sc, R92C_TRXFF_BNDY + 2, dmasize - 1);