MRMAC0
u32 mrmac0 = ioread32(etha->addr + MRMAC0);
iowrite32((mac[0] << 8) | mac[1], etha->addr + MRMAC0);
rtsn_write(priv, MRMAC0, (mac_addr[0] << 8) | mac_addr[1]);
mrmac0 = rtsn_read(priv, MRMAC0);