tree: https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git gpio-charger-mentioned head: f9e5824140b913437cc820c3f8bb33353ee4961d commit: f6d984418ffde19322fd149105200224ac2bc089 [54/55] gpiolib: split character device into gpiolib-cdev config: powerpc-randconfig-r002-20200611 (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project bc2b70982be8f5250cd0082a7190f8b417bd4dfe) 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 powerpc cross compiling tool for clang build # apt-get install binutils-powerpc-linux-gnu git checkout f6d984418ffde19322fd149105200224ac2bc089 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang 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 warnings (new ones prefixed by >>, old ones prefixed by <<): int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) ^ drivers/gpio/gpiolib-cdev.c:1127:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) ^ static void gpiolib_cdev_unregister(struct gpio_device *gdev) ^ drivers/gpio/gpiolib-cdev.c:1145:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void gpiolib_cdev_unregister(struct gpio_device *gdev) ^ static 2 warnings generated. vim +/gpiolib_cdev_register +1127 drivers/gpio/gpiolib-cdev.c 1126 1128 { 1129 int ret; 1130 1131 cdev_init(&gdev->chrdev, &gpio_fileops); 1132 gdev->chrdev.owner = THIS_MODULE; 1133 gdev->dev.devt = MKDEV(MAJOR(devt), gdev->id); 1134 1135 ret = cdev_device_add(&gdev->chrdev, &gdev->dev); 1136 if (ret) 1137 return ret; 1138 1139 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n", 1140 MAJOR(devt), gdev->id); 1141 1142 return 0; 1143 } 1144 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org