Hi Raymond, FYI, the error/warning still remains. tree: https://github.com/intel/linux-intel-lts.git 5.10/yocto head: 1941d4b82f36cc6ecc513f3e496ad62726d00514 commit: 0bce160955505f13b1c53ce6c48eaa49f3dd472d [18526/20368] mfd: intel-ehl-gpio: Introduce MFD framework to PSE GPIO/TGPIO config: i386-allyesconfig (https://download.01.org/0day-ci/archive/20220117/202201170451.nBuGNQtN-lk...) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 650fc40b6d8d9a5869b4fca525d5f237b0ee2803) 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://github.com/intel/linux-intel-lts/commit/0bce160955505f13b1c53ce6c... git remote add intel-lts https://github.com/intel/linux-intel-lts.git git fetch --no-tags intel-lts 5.10/yocto git checkout 0bce160955505f13b1c53ce6c48eaa49f3dd472d # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/gpio/ drivers/gpu/drm/i915/ drivers/ptp/ 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 >>): void ehl_pse_gpio_free(struct gpio_chip *chip, unsigned int offset) ^ drivers/gpio/gpio-ehl-pse-plat.c:79:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void ehl_pse_gpio_free(struct gpio_chip *chip, unsigned int offset) ^ static drivers/gpio/gpio-ehl-pse-plat.c:175:6: warning: mixing declarations and code is a C99 extension [-Wdeclaration-after-statement] u32 reg_gpdr = intel_gpio_readl(priv->reg_base, GPDR); ^ drivers/gpio/gpio-ehl-pse-plat.c:378:10: warning: incompatible pointer to integer conversion returning 'void *' from a function with result type 'int' [-Wint-conversion] return NULL; ^~~~ include/linux/stddef.h:8:14: note: expanded from macro 'NULL' #define NULL ((void *)0) ^~~~~~~~~~~ drivers/gpio/gpio-ehl-pse-plat.c:382:10: warning: incompatible pointer to integer conversion returning 'void *' from a function with result type 'int' [-Wint-conversion] return NULL; ^~~~ include/linux/stddef.h:8:14: note: expanded from macro 'NULL' #define NULL ((void *)0) ^~~~~~~~~~~ drivers/gpio/gpio-ehl-pse-plat.c:365:16: warning: unused variable 'base' [-Wunused-variable] void __iomem *base; ^ 5 warnings generated. -- if (scaled_ppm < 0) { ^~~~~~~~~~~~~~ drivers/ptp/ptp-intel-tgpio-plat.c:247:9: note: uninitialized use occurs here reg |= isgn << 31; ^~~~ drivers/ptp/ptp-intel-tgpio-plat.c:234:2: note: remove the 'if' if its condition is always true if (scaled_ppm < 0) { ^~~~~~~~~~~~~~~~~~~~ drivers/ptp/ptp-intel-tgpio-plat.c:229:13: note: initialize the variable 'isgn' to silence this warning bool isgn; ^ = 0 1 warning generated. vim +/ehl_pse_gpio_free +79 drivers/gpio/gpio-ehl-pse-plat.c 78 80 { 81 /* decrease runtime_usage counter */ 82 pm_runtime_put_sync(chip->parent); 83 } 84 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org