Hi "Uwe, I love your patch! Yet something to improve: [auto build test ERROR on e8b767f5e04097aaedcd6e06e2270f9fe5282696] url: https://github.com/intel-lab-lkp/linux/commits/Uwe-Kleine-K-nig/gpio-pcf857x-Make-teardown-callback-return-void/20220402-010754 base: e8b767f5e04097aaedcd6e06e2270f9fe5282696 config: arm-davinci_all_defconfig (https://download.01.org/0day-ci/archive/20220403/202204032242.oF5ZiIfP-lkp@xxxxxxxxx/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project c4a1b07d0979e7ff20d7d541af666d822d66b566) 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 arm cross compiling tool for clang build # apt-get install binutils-arm-linux-gnueabi # https://github.com/intel-lab-lkp/linux/commit/a3a8679599814e10a75617073b06db14ef794a54 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Uwe-Kleine-K-nig/gpio-pcf857x-Make-teardown-callback-return-void/20220402-010754 git checkout a3a8679599814e10a75617073b06db14ef794a54 # 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=arm SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All errors (new ones prefixed by >>): >> arch/arm/mach-davinci/board-dm644x-evm.c:499:1: error: non-void function does not return a value [-Werror,-Wreturn-type] } ^ >> arch/arm/mach-davinci/board-dm644x-evm.c:504:14: error: incompatible function pointer types initializing 'void (*)(struct i2c_client *, int, unsigned int, void *)' with an expression of type 'int (struct i2c_client *, int, unsigned int, void *)' [-Werror,-Wincompatible-function-pointer-types] .teardown = evm_u35_teardown, ^~~~~~~~~~~~~~~~ 2 errors generated. vim +499 arch/arm/mach-davinci/board-dm644x-evm.c 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 488 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 489 static int 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 490 evm_u35_teardown(struct i2c_client *client, int gpio, unsigned ngpio, void *c) 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 491 { 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 492 gpio_free(gpio + 7); 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 493 gpio_free(gpio + 6); 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 494 gpio_free(gpio + 5); 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 495 gpio_free(gpio + 3); 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 496 gpio_free(gpio + 2); 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 497 gpio_free(gpio + 1); 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 498 gpio_free(gpio + 0); 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 @499 } 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 500 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 501 static struct pcf857x_platform_data pcf_data_u35 = { 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 502 .gpio_base = PCF_Uxx_BASE(2), 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 503 .setup = evm_u35_setup, 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 @504 .teardown = evm_u35_teardown, 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 505 }; 7bff3c4ce44ea48 arch/arm/mach-davinci/board-evm.c David Brownell 2008-09-07 506 -- 0-DAY CI Kernel Test Service https://01.org/lkp