Hi Thomas, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 7cf726a59435301046250c42131554d9ccc566b8 commit: 7505576d1c1ac0cfe85fdf90999433dd8b673012 MIPS: add support for SGI Octane (IP30) date: 12 months ago config: mips-randconfig-r021-20201019 (attached as .config) compiler: mips64-linux-gcc (GCC) 9.3.0 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/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 7505576d1c1ac0cfe85fdf90999433dd8b673012 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=mips 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 >>): 122 | void __init plat_mem_setup(void) | ^~~~~~~~~~~~~~ -- 15 | void prom_putchar(char c) | ^~~~~~~~~~~~ vim +/plat_mem_setup +122 arch/mips/sgi-ip30/ip30-setup.c 118 119 /** 120 * plat_mem_setup - despite the name, misc setup happens here. 121 */ 123 { 124 ip30_mem_init(); 125 126 /* XXX: Hard lock on /sbin/init if this flag isn't specified. */ 127 prom_flags |= PROM_FLAG_DONT_FREE_TEMP; 128 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org