BE_BRI_TXCFG
BE_BRI_TXCFG, BE_BR_TXCFG_FIFO | BE_BR_TXCFG_ENABLE);
v = bus_space_read_4(t, br, BE_BRI_TXCFG);
bus_space_write_4(t, br, BE_BRI_TXCFG, v);
bus_space_write_4(t, br, BE_BRI_TXCFG, 0);
if (bus_space_read_4(t, br, BE_BRI_TXCFG) == 0)