tree: https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git to-build head: 5fd3eccb73a30251d944935959498ca308848a54 commit: cae2b1064d5a147bffbd0447f9cd264b140b7f72 [37/41] net: split out ndo_siowandev ioctl config: x86_64-allyesconfig (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/commi... git remote add arnd-playground https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git git fetch --no-tags arnd-playground to-build git checkout cae2b1064d5a147bffbd0447f9cd264b140b7f72 # save the attached .config to linux build tree make W=1 W=1 ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): 61 | int lmc_proto_ioctl(lmc_softc_t *sc, struct if_settings *ifs) | ^~~~~~~~~~~~~~~ vim +/lmc_proto_ioctl +61 drivers/net/wan/lmc/lmc_proto.c 60 62 { 63 if (sc->if_type == LMC_PPP) 64 return hdlc_ioctl(sc->lmc_device, ifs); 65 return -EOPNOTSUPP; 66 } 67 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org