Hi Luiz, First bad commit (maybe != root cause): tree: https://github.com/frank-w/BPI-R2-4.14 5.17-r2pro-hdmiv5 head: 2fc65b46be5ea69f66ce812f2c847c074a0eb1b6 commit: 0cde4ee872bb3a40c6953e5f9df02826fa9a12cb [49/97] net: dsa: realtek: add new mdio interface for drivers config: microblaze-buildonly-randconfig-r002-20220210 (https://download.01.org/0day-ci/archive/20220210/202202101531.qXWeBaCv-lk...) compiler: microblaze-linux-gcc (GCC) 11.2.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/frank-w/BPI-R2-4.14/commit/0cde4ee872bb3a40c6953e5f9df... git remote add frank-w-bpi-r2-4.14 https://github.com/frank-w/BPI-R2-4.14 git fetch --no-tags frank-w-bpi-r2-4.14 5.17-r2pro-hdmiv5 git checkout 0cde4ee872bb3a40c6953e5f9df02826fa9a12cb # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=microblaze SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): microblaze-linux-ld: drivers/net/dsa/realtek/realtek-smi.o:(.rodata+0x2d8): undefined reference to `rtl8366rb_variant' --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org