Hi Thomas, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: ac30d8ce28d61c05ac3a8b1452e889371136f3af commit: 7fd70c65faacd39628ba5f670be6490010c8132f ARM: irqstat: Get rid of duplicated declaration date: 3 months ago config: arm-randconfig-r003-20210214 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c9439ca36342fb6013187d0a69aef92736951476) 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=7fd70c65faacd39628ba5f670be6490010c8132f git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 7fd70c65faacd39628ba5f670be6490010c8132f # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): >> drivers/rtc/rtc-pcf8523.c:35:9: warning: 'REG_OFFSET' macro redefined [-Wmacro-redefined] #define REG_OFFSET 0x0e ^ arch/arm/mach-ixp4xx/include/mach/platform.h:23:9: note: previous definition is here #define REG_OFFSET 0 ^ 1 warning generated. vim +/REG_OFFSET +35 drivers/rtc/rtc-pcf8523.c f803f0d079ded4 Thierry Reding 2012-12-17 34 bc3bee02527252 Russell King 2017-09-29 @35 #define REG_OFFSET 0x0e bc3bee02527252 Russell King 2017-09-29 36 #define REG_OFFSET_MODE BIT(7) bc3bee02527252 Russell King 2017-09-29 37 :::::: The code at line 35 was first introduced by commit :::::: bc3bee0252725240ffa62180d387cc245179c549 rtc: pcf8523: add support for trimming the RTC oscillator :::::: TO: Russell King :::::: CC: Alexandre Belloni --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org