tree: git://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git sched/headers head: 4c707c1c0de83967079b4e385012fa5b00e2cd11 commit: a8084e440c4391f574018f45590e8666b4ddda5f [2355/2384] headers/deps: driver/core: Optimize <linux/device/driver.h> dependencies, remove <linux/module.h> inclusion config: mips-randconfig-r023-20220124 (https://download.01.org/0day-ci/archive/20220124/202201242143.d1yXnKnX-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 sched/headers git checkout a8084e440c4391f574018f45590e8666b4ddda5f # 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/dec/ 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 >>): 33 | static int __init dec_add_devices(void) | ^~~~~~~~~~~~~~~ 40 | device_initcall(dec_add_devices); | ^~~~~~~~~~~~~~~ arch/mips/dec/platform.c:25:31: warning: 'dec_rtc_device' defined but not used [-Wunused-variable] 25 | static struct platform_device dec_rtc_device = { | ^~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +33 arch/mips/dec/platform.c fae67ad431146d Maciej W. Rozycki 2014-06-06 32 fae67ad431146d Maciej W. Rozycki 2014-06-06 @33 static int __init dec_add_devices(void) fae67ad431146d Maciej W. Rozycki 2014-06-06 34 { fae67ad431146d Maciej W. Rozycki 2014-06-06 35 dec_rtc_resources[0].start = RTC_PORT(0); fae67ad431146d Maciej W. Rozycki 2014-06-06 36 dec_rtc_resources[0].end = RTC_PORT(0) + dec_kn_slot_size - 1; fae67ad431146d Maciej W. Rozycki 2014-06-06 37 return platform_device_register(&dec_rtc_device); fae67ad431146d Maciej W. Rozycki 2014-06-06 38 } fae67ad431146d Maciej W. Rozycki 2014-06-06 39 fae67ad431146d Maciej W. Rozycki 2014-06-06 @40 device_initcall(dec_add_devices); :::::: The code at line 33 was first introduced by commit :::::: fae67ad431146d2584dd813cbc198400a477aa53 arch/mips/dec: switch DECstation systems to rtc-cmos :::::: TO: Maciej W. Rozycki <macro(a)linux-mips.org&gt; :::::: CC: Linus Torvalds <torvalds(a)linux-foundation.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org