[kbuild-all] arch/powerpc/platforms/microwatt/rng.c:17:5: error: no previous prototype for 'microwatt_get_random_darn'

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: debe436e77c72fcee804fb867f275e6d31aa999c commit: c25769fddaec13509b6cdc7ad17458f239c4cee7 powerpc/microwatt: Add support for hardware random number generator date: 5 months ago config: powerpc64-buildonly-randconfig-r002-20210929 (attached as .config) compiler: powerpc64le-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/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 c25769fddaec13509b6cdc7ad17458f239c4cee7 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=powerpc 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 >>): 17 | int microwatt_get_random_darn(unsigned long *v) | ^~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors vim +/microwatt_get_random_darn +17 arch/powerpc/platforms/microwatt/rng.c 16 18 { 19 unsigned long val; 20 21 /* Using DARN with L=1 - 64-bit conditioned random number */ 22 asm volatile(PPC_DARN(%0, 1) : "=r"(val)); 23 24 if (val == DARN_ERR) 25 return 0; 26 27 *v = val; 28 29 return 1; 30 } 31 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org