Hi Paul, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 8ed710da2873c2aeb3bb805864a699affaf1d03b commit: c434b9f80b0923e6460031b0fd964f8b0bf3c6a6 MIPS: Kconfig: add MIPS_GENERIC_KERNEL symbol date: 2 years, 3 months ago config: mips-buildonly-randconfig-r005-20221208 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 mips cross compiling tool for clang build # apt-get install binutils-mipsel-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c434b9f80b0923e6460031b0fd964f8b0bf3c6a6 git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout c434b9f80b0923e6460031b0fd964f8b0bf3c6a6 # 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=mips SHELL=/bin/bash arch/mips/loongson32/common/ lib/zstd/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot All warnings (new ones prefixed by >>): >> arch/mips/loongson32/common/time.c:50:13: warning: no previous prototype for function 'ls1x_pwmtimer_init' [-Wmissing-prototypes] void __init ls1x_pwmtimer_init(void) ^ arch/mips/loongson32/common/time.c:50:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void __init ls1x_pwmtimer_init(void) ^ static 1 warning generated. vim +/ls1x_pwmtimer_init +50 arch/mips/loongson32/common/time.c c5d58e9e79dd8d arch/mips/loongson1/common/time.c Kelvin Cheung 2014-10-10 49 c5d58e9e79dd8d arch/mips/loongson1/common/time.c Kelvin Cheung 2014-10-10 @50 void __init ls1x_pwmtimer_init(void) c5d58e9e79dd8d arch/mips/loongson1/common/time.c Kelvin Cheung 2014-10-10 51 { 4bdc0d676a6431 arch/mips/loongson32/common/time.c Christoph Hellwig 2020-01-06 52 timer_reg_base = ioremap(LS1X_TIMER_BASE, SZ_16); 9ec88b60cb481a arch/mips/loongson32/common/time.c Kelvin Cheung 2016-04-06 53 if (!timer_reg_base) c5d58e9e79dd8d arch/mips/loongson1/common/time.c Kelvin Cheung 2014-10-10 54 panic("Failed to remap timer registers"); c5d58e9e79dd8d arch/mips/loongson1/common/time.c Kelvin Cheung 2014-10-10 55 c5d58e9e79dd8d arch/mips/loongson1/common/time.c Kelvin Cheung 2014-10-10 56 ls1x_jiffies_per_tick = DIV_ROUND_CLOSEST(mips_hpt_frequency, HZ); c5d58e9e79dd8d arch/mips/loongson1/common/time.c Kelvin Cheung 2014-10-10 57 c5d58e9e79dd8d arch/mips/loongson1/common/time.c Kelvin Cheung 2014-10-10 58 ls1x_pwmtimer_set_period(ls1x_jiffies_per_tick); c5d58e9e79dd8d arch/mips/loongson1/common/time.c Kelvin Cheung 2014-10-10 59 ls1x_pwmtimer_restart(); c5d58e9e79dd8d arch/mips/loongson1/common/time.c Kelvin Cheung 2014-10-10 60 } c5d58e9e79dd8d arch/mips/loongson1/common/time.c Kelvin Cheung 2014-10-10 61 :::::: The code at line 50 was first introduced by commit :::::: c5d58e9e79dd8d687454915fc4e845434f973175 MIPS: Loongson1B: Add a clockevent/clocksource using PWM Timer :::::: TO: Kelvin Cheung :::::: CC: Ralf Baechle -- 0-DAY CI Kernel Test Service https://01.org/lkp