Hi Frank, FYI, the error/warning still remains. tree: https://github.com/frank-w/BPI-R2-4.14 5.9-mt76eeprom head: 2231147c92c4f500aaea9c38f66ccbc4a6688561 commit: 641b9cb942b2e3db4bbadd5286c450678a556da1 [42/51] mt6625l: add changes outside driver dir config: arm64-randconfig-r012-20201029 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 772aaa602383cf82795572ebcd86b0e660f3579f) 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://github.com/frank-w/BPI-R2-4.14/commit/641b9cb942b2e3db4bbadd5286c... git remote add frank-w-bpi-r2-4.14 https://github.com/frank-w/BPI-R2-4.14 git fetch --no-tags frank-w-bpi-r2-4.14 5.9-mt76eeprom git checkout 641b9cb942b2e3db4bbadd5286c450678a556da1 # 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 >>): struct regmap *pwrap_node_to_regmap(struct device_node *np) ^ drivers/soc/mediatek/mtk-pmic-wrap.c:2022:1: note: declare 'static' if the function is not intended to be used outside of this translation unit struct regmap *pwrap_node_to_regmap(struct device_node *np) ^ static 1 warning generated. vim +/pwrap_node_to_regmap +2022 drivers/soc/mediatek/mtk-pmic-wrap.c 2021 2023 { 2024 struct platform_device *pdev; 2025 struct pmic_wrapper *wrp; 2026 pdev = of_find_device_by_node(np); 2027 if (!pdev) 2028 return ERR_PTR(-ENODEV); 2029 wrp = platform_get_drvdata(pdev); 2030 return wrp->regmap; 2031 } 2032 EXPORT_SYMBOL_GPL(pwrap_node_to_regmap); 2033 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org