tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 0c18f29aae7ce3dadd26d8ee3505d07cc982df75 commit: 97e4910232fa1f81e806aa60c25a0450276d99a2 linux/compiler-clang.h: define HAVE_BUILTIN_BSWAP* date: 3 months ago config: powerpc-randconfig-r021-20210623 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project b259740801d3515810ecc15bf0c24b0d476a1608) 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 # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 97e4910232fa1f81e806aa60c25a0450276d99a2 # 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 >>): In file included from drivers/media/common/saa7146/saa7146_hlp.c:4: In file included from include/linux/kernel.h:11: In file included from include/linux/bitops.h:32: In file included from arch/powerpc/include/asm/bitops.h:62: arch/powerpc/include/asm/barrier.h:49:9: warning: '__lwsync' macro redefined [-Wmacro-redefined] #define __lwsync() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory") ^ <built-in>:309:9: note: previous definition is here #define __lwsync __builtin_ppc_lwsync ^ int saa7146_enable_overlay(struct saa7146_fh *fh) ^ 2 warnings generated. vim +/saa7146_enable_overlay +648 drivers/media/common/saa7146/saa7146_hlp.c ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 647 ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 @648 int saa7146_enable_overlay(struct saa7146_fh *fh) ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 649 { ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 650 struct saa7146_dev *dev = fh->dev; ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 651 struct saa7146_vv *vv = dev->vv_data; ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 652 5da545ad08a3c6 drivers/media/common/saa7146_hlp.c Hans Verkuil 2012-05-01 653 saa7146_set_window(dev, vv->ov.win.w.width, vv->ov.win.w.height, vv->ov.win.field); 5da545ad08a3c6 drivers/media/common/saa7146_hlp.c Hans Verkuil 2012-05-01 654 saa7146_set_position(dev, vv->ov.win.w.left, vv->ov.win.w.top, vv->ov.win.w.height, vv->ov.win.field, vv->ov_fmt->pixelformat); ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 655 saa7146_set_output_format(dev, vv->ov_fmt->trans); ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 656 saa7146_set_clipping_rect(fh); ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 657 ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 658 /* enable video dma1 */ ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 659 saa7146_write(dev, MC1, (MASK_06 | MASK_22)); ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 660 return 0; ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 661 } ^1da177e4c3f41 drivers/media/common/saa7146_hlp.c Linus Torvalds 2005-04-16 662 :::::: The code at line 648 was first introduced by commit :::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2 :::::: TO: Linus Torvalds <torvalds(a)ppc970.osdl.org&gt; :::::: CC: Linus Torvalds <torvalds(a)ppc970.osdl.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org