Hi Junjie, kernel test robot noticed the following build warnings:
[auto build test WARNING on lee-backlight/for-backlight-next] [also build test WARNING on lee-leds/for-leds-next linus/master v6.18-rc3 next-20251027] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Junjie-Cao/backlight-aw99706-Add-support-for-Awinic-AW99706-backlight/20251026-214135 base: https://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight.git for-backlight-next patch link: https://lore.kernel.org/r/20251026123923.1531727-3-caojunjie650%40gmail.com patch subject: [PATCH 2/2] backlight: aw99706: Add support for Awinic AW99706 backlight config: powerpc-allmodconfig (https://download.01.org/0day-ci/archive/20251028/[email protected]/config) compiler: powerpc64-linux-gcc (GCC) 15.1.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251028/[email protected]/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <[email protected]> | Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/ All warnings (new ones prefixed by >>): In file included from include/linux/fortify-string.h:5, from include/linux/string.h:382, from arch/powerpc/include/asm/paca.h:16, from arch/powerpc/include/asm/current.h:13, from include/linux/sched.h:12, from include/linux/ratelimit.h:6, from include/linux/dev_printk.h:16, from include/linux/device.h:15, from include/linux/backlight.h:12, from drivers/video/backlight/aw99706.c:12: drivers/video/backlight/aw99706.c: In function 'aw99706_bl_enable': >> include/linux/bitfield.h:172:27: warning: 'val' is used uninitialized >> [-Wuninitialized] 172 | *(_reg_p) &= ~(_mask); \ | ^~ drivers/video/backlight/aw99706.c:325:9: note: in expansion of macro 'FIELD_MODIFY' 325 | FIELD_MODIFY(AW99706_BACKLIGHT_EN_MASK, &val, en); | ^~~~~~~~~~~~ drivers/video/backlight/aw99706.c:323:12: note: 'val' was declared here 323 | u8 val; | ^~~ vim +/val +172 include/linux/bitfield.h e2192de59e457a Johannes Berg 2023-01-18 120 e2192de59e457a Johannes Berg 2023-01-18 121 /** e2192de59e457a Johannes Berg 2023-01-18 122 * FIELD_PREP_CONST() - prepare a constant bitfield element e2192de59e457a Johannes Berg 2023-01-18 123 * @_mask: shifted mask defining the field's length and position e2192de59e457a Johannes Berg 2023-01-18 124 * @_val: value to put in the field e2192de59e457a Johannes Berg 2023-01-18 125 * e2192de59e457a Johannes Berg 2023-01-18 126 * FIELD_PREP_CONST() masks and shifts up the value. The result should e2192de59e457a Johannes Berg 2023-01-18 127 * be combined with other fields of the bitfield using logical OR. e2192de59e457a Johannes Berg 2023-01-18 128 * e2192de59e457a Johannes Berg 2023-01-18 129 * Unlike FIELD_PREP() this is a constant expression and can therefore e2192de59e457a Johannes Berg 2023-01-18 130 * be used in initializers. Error checking is less comfortable for this e2192de59e457a Johannes Berg 2023-01-18 131 * version, and non-constant masks cannot be used. e2192de59e457a Johannes Berg 2023-01-18 132 */ e2192de59e457a Johannes Berg 2023-01-18 133 #define FIELD_PREP_CONST(_mask, _val) \ e2192de59e457a Johannes Berg 2023-01-18 134 ( \ e2192de59e457a Johannes Berg 2023-01-18 135 /* mask must be non-zero */ \ e2192de59e457a Johannes Berg 2023-01-18 136 BUILD_BUG_ON_ZERO((_mask) == 0) + \ e2192de59e457a Johannes Berg 2023-01-18 137 /* check if value fits */ \ e2192de59e457a Johannes Berg 2023-01-18 138 BUILD_BUG_ON_ZERO(~((_mask) >> __bf_shf(_mask)) & (_val)) + \ e2192de59e457a Johannes Berg 2023-01-18 139 /* check if mask is contiguous */ \ e2192de59e457a Johannes Berg 2023-01-18 140 __BF_CHECK_POW2((_mask) + (1ULL << __bf_shf(_mask))) + \ e2192de59e457a Johannes Berg 2023-01-18 141 /* and create the value */ \ e2192de59e457a Johannes Berg 2023-01-18 142 (((typeof(_mask))(_val) << __bf_shf(_mask)) & (_mask)) \ e2192de59e457a Johannes Berg 2023-01-18 143 ) e2192de59e457a Johannes Berg 2023-01-18 144 3e9b3112ec74f1 Jakub Kicinski 2016-08-31 145 /** 3e9b3112ec74f1 Jakub Kicinski 2016-08-31 146 * FIELD_GET() - extract a bitfield element 3e9b3112ec74f1 Jakub Kicinski 2016-08-31 147 * @_mask: shifted mask defining the field's length and position 7240767450d6d8 Masahiro Yamada 2017-10-03 148 * @_reg: value of entire bitfield 3e9b3112ec74f1 Jakub Kicinski 2016-08-31 149 * 3e9b3112ec74f1 Jakub Kicinski 2016-08-31 150 * FIELD_GET() extracts the field specified by @_mask from the 3e9b3112ec74f1 Jakub Kicinski 2016-08-31 151 * bitfield passed in as @_reg by masking and shifting it down. 3e9b3112ec74f1 Jakub Kicinski 2016-08-31 152 */ 3e9b3112ec74f1 Jakub Kicinski 2016-08-31 153 #define FIELD_GET(_mask, _reg) \ 3e9b3112ec74f1 Jakub Kicinski 2016-08-31 154 ({ \ 3e9b3112ec74f1 Jakub Kicinski 2016-08-31 155 __BF_FIELD_CHECK(_mask, _reg, 0U, "FIELD_GET: "); \ 3e9b3112ec74f1 Jakub Kicinski 2016-08-31 156 (typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask)); \ 3e9b3112ec74f1 Jakub Kicinski 2016-08-31 157 }) 3e9b3112ec74f1 Jakub Kicinski 2016-08-31 158 a256ae22570ee4 Luo Jie 2025-04-17 159 /** a256ae22570ee4 Luo Jie 2025-04-17 160 * FIELD_MODIFY() - modify a bitfield element a256ae22570ee4 Luo Jie 2025-04-17 161 * @_mask: shifted mask defining the field's length and position a256ae22570ee4 Luo Jie 2025-04-17 162 * @_reg_p: pointer to the memory that should be updated a256ae22570ee4 Luo Jie 2025-04-17 163 * @_val: value to store in the bitfield a256ae22570ee4 Luo Jie 2025-04-17 164 * a256ae22570ee4 Luo Jie 2025-04-17 165 * FIELD_MODIFY() modifies the set of bits in @_reg_p specified by @_mask, a256ae22570ee4 Luo Jie 2025-04-17 166 * by replacing them with the bitfield value passed in as @_val. a256ae22570ee4 Luo Jie 2025-04-17 167 */ a256ae22570ee4 Luo Jie 2025-04-17 168 #define FIELD_MODIFY(_mask, _reg_p, _val) \ a256ae22570ee4 Luo Jie 2025-04-17 169 ({ \ a256ae22570ee4 Luo Jie 2025-04-17 170 typecheck_pointer(_reg_p); \ a256ae22570ee4 Luo Jie 2025-04-17 171 __BF_FIELD_CHECK(_mask, *(_reg_p), _val, "FIELD_MODIFY: "); \ a256ae22570ee4 Luo Jie 2025-04-17 @172 *(_reg_p) &= ~(_mask); \ a256ae22570ee4 Luo Jie 2025-04-17 173 *(_reg_p) |= (((typeof(_mask))(_val) << __bf_shf(_mask)) & (_mask)); \ a256ae22570ee4 Luo Jie 2025-04-17 174 }) a256ae22570ee4 Luo Jie 2025-04-17 175 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
