tree: https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git v5.10/ffa head: 9ce10ec03a756e0d3eccc023202850b73f32763b commit: 3f6a528cbb0b1a6342035baf9f44b32947989346 [5/9] firmware: arm_ffa: Add initial Arm FFA driver support config: arm64-randconfig-r032-20201113 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 9e0c35655b6e8186baef8840b26ba4090503b554) 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 # install arm64 cross compiling tool for clang build # apt-get install binutils-aarch64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/co... git remote add skn https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git git fetch --no-tags skn v5.10/ffa git checkout 3f6a528cbb0b1a6342035baf9f44b32947989346 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 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 >>): int __init arm_ffa_bus_init(void) ^ drivers/firmware/arm_ffa/bus.c:173:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int __init arm_ffa_bus_init(void) ^ static void __exit arm_ffa_bus_exit(void) ^ drivers/firmware/arm_ffa/bus.c:192:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void __exit arm_ffa_bus_exit(void) ^ static 2 warnings generated. vim +/arm_ffa_bus_init +173 drivers/firmware/arm_ffa/bus.c 172 174 { 175 int ret; 176 177 ret = alloc_chrdev_region(&ffa_devt, 0, FFA_MAX_CDEVS, DEVICE_NAME); 178 if (ret) { 179 pr_err("failed to allocate char dev region\n"); 180 return ret; 181 } 182 183 ret = bus_register(&ffa_bus_type); 184 if (ret) { 185 pr_err("ffa bus register failed (%d)\n", ret); 186 unregister_chrdev_region(ffa_devt, FFA_MAX_CDEVS); 187 } 188 189 return ret; 190 } 191 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org