tree: https://github.com/jpirko/linux_mlxsw linecards head: dd17eb77d784c506130ff7ee7ee6f323b8238644 commit: ed0d82437b845ea00d5d09d2239062cdeeccbf82 [14/95] mlxsw: spectrum: Introduce port mapping change event processing 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://github.com/jpirko/linux_mlxsw/commit/ed0d82437b845ea00d5d09d22390... git remote add jpirko-mlxsw https://github.com/jpirko/linux_mlxsw git fetch --no-tags jpirko-mlxsw linecards git checkout ed0d82437b845ea00d5d09d2239062cdeeccbf82 # 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 >>): drivers/net/ethernet/mellanox/mlxsw/spectrum.c:534:1: error: return type defaults to 'int' [-Werror=return-type] 534 | mlxsw_sp_port_module_info_get(struct mlxsw_sp *mlxsw_sp, u8 local_port, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +/mlxsw_sp_port_module_info_get +534 drivers/net/ethernet/mellanox/mlxsw/spectrum.c 533 535 struct mlxsw_sp_port_mapping *port_mapping) 536 { 537 char pmlp_pl[MLXSW_REG_PMLP_LEN]; 538 int err; 539 540 mlxsw_reg_pmlp_pack(pmlp_pl, local_port); 541 err = mlxsw_reg_query(mlxsw_sp->core, MLXSW_REG(pmlp), pmlp_pl); 542 if (err) 543 return err; 544 return mlxsw_sp_port_module_info_parse(mlxsw_sp, local_port, 545 pmlp_pl, port_mapping); 546 } 547 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org