tree: git://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git master head: 391ce485ced0e47bf8d2ce8bc32bb87887e16656 commit: 8e681df39108b99bab14c70b640024589fa9fa7b [2018/2375] headers/deps: fs: Optimize <linux/seq_file.h> dependencies config: mips-vocore2_defconfig (https://download.01.org/0day-ci/archive/20220110/202201101856.jfl5AsHo-lk...) compiler: mipsel-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://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git/commit/?id=... git remote add mingo-tip git://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git git fetch --no-tags mingo-tip master git checkout 8e681df39108b99bab14c70b640024589fa9fa7b # 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=mips SHELL=/bin/bash arch/mips/ralink/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All error/warnings (new ones prefixed by >>): 34 | static int __init bootrom_setup(void) | ^~~~~~~~~~~~~ 40 | postcore_initcall(bootrom_setup); | ^~~~~~~~~~~~~~~~~ arch/mips/ralink/bootrom.c:27:37: warning: 'bootrom_file_ops' defined but not used [-Wunused-const-variable=] 27 | static const struct file_operations bootrom_file_ops = { | ^~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +34 arch/mips/ralink/bootrom.c 7a1a44c909fcb4 John Crispin 2013-05-21 33 389500696810f5 Christophe JAILLET 2020-05-31 @34 static int __init bootrom_setup(void) 7a1a44c909fcb4 John Crispin 2013-05-21 35 { 4c90de4dd33d90 Greg Kroah-Hartman 2019-01-22 36 debugfs_create_file("bootrom", 0444, NULL, NULL, &bootrom_file_ops); 7a1a44c909fcb4 John Crispin 2013-05-21 37 return 0; 7a1a44c909fcb4 John Crispin 2013-05-21 38 } 7a1a44c909fcb4 John Crispin 2013-05-21 39 7a1a44c909fcb4 John Crispin 2013-05-21 @40 postcore_initcall(bootrom_setup); :::::: The code at line 34 was first introduced by commit :::::: 389500696810f5aa8fc1fe6f375b9dabd111e1d6 MIPS: ralink: bootrom: mark a function as __init to save some memory :::::: TO: Christophe JAILLET <christophe.jaillet(a)wanadoo.fr&gt; :::::: CC: Thomas Bogendoerfer <tsbogend(a)alpha.franken.de&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org