Hi Arnd, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 0d1409e4ff08aa4a9a254d3f723410db32aa7552 commit: 8c1fb11b8a77dc489a8ef6d96c38c1297b629d06 ARM: s3c: enable s3c24xx multiplatform support date: 8 months ago config: arm-randconfig-r025-20221209 compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 6e4cea55f0d1104408b26ac574566a0e4de48036) 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://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8c1fb11b8a77dc489a8ef6d96c38c1297b629d06 git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 8c1fb11b8a77dc489a8ef6d96c38c1297b629d06 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash arch/arm/mach-mmp/ arch/arm/mach-pxa/ drivers/hwmon/ drivers/video/backlight/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot All warnings (new ones prefixed by >>): >> arch/arm/mach-pxa/balloon3.c:85:12: warning: no previous prototype for function 'parse_balloon3_features' [-Wmissing-prototypes] int __init parse_balloon3_features(char *arg) ^ arch/arm/mach-pxa/balloon3.c:85:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int __init parse_balloon3_features(char *arg) ^ static 1 warning generated. -- >> arch/arm/mach-pxa/trizeps4.c:279:6: warning: no previous prototype for function 'board_pcmcia_power' [-Wmissing-prototypes] void board_pcmcia_power(int power) ^ arch/arm/mach-pxa/trizeps4.c:279:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void board_pcmcia_power(int power) ^ static 1 warning generated. -- >> arch/arm/mach-pxa/corgi_pm.c:137:15: warning: no previous prototype for function 'corgipm_read_devdata' [-Wmissing-prototypes] unsigned long corgipm_read_devdata(int type) ^ arch/arm/mach-pxa/corgi_pm.c:137:1: note: declare 'static' if the function is not intended to be used outside of this translation unit unsigned long corgipm_read_devdata(int type) ^ static 1 warning generated. -- >> arch/arm/mach-pxa/spitz_pm.c:170:15: warning: no previous prototype for function 'spitzpm_read_devdata' [-Wmissing-prototypes] unsigned long spitzpm_read_devdata(int type) ^ arch/arm/mach-pxa/spitz_pm.c:170:1: note: declare 'static' if the function is not intended to be used outside of this translation unit unsigned long spitzpm_read_devdata(int type) ^ static 1 warning generated. -- >> drivers/hwmon/max1111.c:83:5: warning: no previous prototype for function 'max1111_read_channel' [-Wmissing-prototypes] int max1111_read_channel(int channel) ^ drivers/hwmon/max1111.c:83:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int max1111_read_channel(int channel) ^ static 1 warning generated. -- >> drivers/video/backlight/tosa_lcd.c:143:5: warning: no previous prototype for function 'tosa_lcd_set_power' [-Wmissing-prototypes] int tosa_lcd_set_power(struct lcd_device *lcd, int power) ^ drivers/video/backlight/tosa_lcd.c:143:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int tosa_lcd_set_power(struct lcd_device *lcd, int power) ^ static 1 warning generated. vim +/parse_balloon3_features +85 arch/arm/mach-pxa/balloon3.c 12a2449c7968696 Marek Vasut 2010-07-27 84 12a2449c7968696 Marek Vasut 2010-07-27 @85 int __init parse_balloon3_features(char *arg) 12a2449c7968696 Marek Vasut 2010-07-27 86 { 12a2449c7968696 Marek Vasut 2010-07-27 87 if (!arg) 12a2449c7968696 Marek Vasut 2010-07-27 88 return 0; 12a2449c7968696 Marek Vasut 2010-07-27 89 4fce45b44bdbf29 Daniel Walter 2014-08-08 90 return kstrtoul(arg, 0, &balloon3_features_present); 12a2449c7968696 Marek Vasut 2010-07-27 91 } 12a2449c7968696 Marek Vasut 2010-07-27 92 early_param("balloon3_features", parse_balloon3_features); 12a2449c7968696 Marek Vasut 2010-07-27 93 :::::: The code at line 85 was first introduced by commit :::::: 12a2449c79686964a36b17175970a8e1c19b4cf7 [ARM] pxa/balloon3: Machine file cleanup :::::: TO: Marek Vasut :::::: CC: Eric Miao -- 0-DAY CI Kernel Test Service https://01.org/lkp