tree: git://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git sched/headers head: 4c707c1c0de83967079b4e385012fa5b00e2cd11 commit: abe1ece6c06895bf5e7c8f03d10061f5712d8326 [2040/2384] headers/deps: dev/core: Optimize <linux/device.h> dependencies, remove <linux/device_api.h> inclusion config: mips-randconfig-m031-20220124 (https://download.01.org/0day-ci/archive/20220125/202201250357.V6BlaZ0J-lk...) compiler: mips64-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 abe1ece6c06895bf5e7c8f03d10061f5712d8326 # 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/pci/ arch/mips/sgi-ip30/ drivers/media/test-drivers/vidtv/ drivers/usb/chipidea/ drivers/usb/usbip/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): arch/mips/sgi-ip30/ip30-setup.c:123:13: warning: no previous prototype for 'plat_mem_setup' [-Wmissing-prototypes] 123 | void __init plat_mem_setup(void) | ^~~~~~~~~~~~~~ arch/mips/sgi-ip30/ip30-setup.c: In function 'plat_mem_setup': 136 | ioport_resource.start = 0; | ^~~~~~~~~~~~~~~ arch/mips/sgi-ip30/ip30-setup.c:136:9: note: each undeclared identifier is reported only once for each function it appears in vim +/ioport_resource +136 arch/mips/sgi-ip30/ip30-setup.c 7505576d1c1ac0 Thomas Bogendoerfer 2019-10-24 135 7505576d1c1ac0 Thomas Bogendoerfer 2019-10-24 @136 ioport_resource.start = 0; :::::: The code at line 136 was first introduced by commit :::::: 7505576d1c1ac0cfe85fdf90999433dd8b673012 MIPS: add support for SGI Octane (IP30) :::::: TO: Thomas Bogendoerfer <tbogendoerfer(a)suse.de&gt; :::::: CC: Paul Burton <paulburton(a)kernel.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org