Hi Laurent, I love your patch! Perhaps something to improve: [auto build test WARNING on linuxtv-media/master] [also build test WARNING on v5.8-rc1 next-20200614] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Laurent-Pinchart/media-ti-vpe-ca... base: git://linuxtv.org/media_tree.git master config: sh-allmodconfig (attached as .config) compiler: sh4-linux-gcc (GCC) 9.3.0 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 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=sh 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 >>, old ones prefixed by <<): In file included from include/linux/err.h:5, from include/linux/clk.h:12, from drivers/media/platform/ti-vpe/cal.c:12: drivers/media/platform/ti-vpe/cal.h: In function 'cal_write_field': include/linux/bitfield.h:52:28: warning: comparison is always false due to limited range of data type [-Wtype-limits] 52 | BUILD_BUG_ON_MSG((_mask) > (typeof(_reg))~0ull, | ^ include/linux/compiler.h:330:9: note: in definition of macro '__compiletime_assert' 330 | if (!(condition)) | ^~~~~~~~~ include/linux/compiler.h:350:2: note: in expansion of macro '_compiletime_assert' 350 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^~~~~~~~~~~~~~~~~~~ include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert' 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) | ^~~~~~~~~~~~~~~~~~ include/linux/bitfield.h:52:3: note: in expansion of macro 'BUILD_BUG_ON_MSG' 52 | BUILD_BUG_ON_MSG((_mask) > (typeof(_reg))~0ull, | ^~~~~~~~~~~~~~~~ include/linux/bitfield.h:94:3: note: in expansion of macro '__BF_FIELD_CHECK' 94 | __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: "); | ^~~~~~~~~~~~~~~~ 229 | val |= FIELD_PREP(mask, value); | ^~~~~~~~~~ vim +/FIELD_PREP +229 drivers/media/platform/ti-vpe/cal.h 222 223 static inline void cal_write_field(struct cal_dev *cal, u32 offset, u32 value, 224 u32 mask) 225 { 226 u32 val = cal_read(cal, offset); 227 228 val &= ~mask; 230 cal_write(cal, offset, val); 231 } 232 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org