Hi Andrew, FYI, the error/warning still remains. tree: https://github.com/lunn/linux.git v5.6-rc5-net-next-cable-test head: 1a5a3b72038e31837fd0cbdd97b4b7edf2c7eeda commit: 983e4eb3374e9a005faf6ae4e57a91f19b3384f5 [8/21] net: ethtool: netlink: Add support for triggering a cable test config: m68k-allmodconfig (attached as .config) compiler: m68k-linux-gcc (GCC) 9.3.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git checkout 983e4eb3374e9a005faf6ae4e57a91f19b3384f5 # save the attached .config to linux build tree GCC_VERSION=9.3.0 make.cross ARCH=m68k If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): m68k-linux-ld: net/ethtool/cabletest.o: in function `ethnl_act_cable_test': m68k-linux-ld: cabletest.c:(.text+0x102): undefined reference to `phy_start_cable_test' --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org