tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 4b6c093e21d36bede0fd88fd0aeb3b03647260e4 commit: 43b1bb4a9b3e183af12225f56c27164c10d06223 clk: at91: clk-sam9x60-pll: re-factor to support plls with multiple outputs date: 3 weeks ago config: arm-at91_dt_defconfig (attached as .config) compiler: arm-linux-gnueabi-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 git checkout 43b1bb4a9b3e183af12225f56c27164c10d06223 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm 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 >>): drivers/clk/at91/clk-sam9x60-pll.c: In function 'sam9x60_div_pll_compute_div': 334 | u32 divid, best_div; | ^~~~~~~~ # 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 43b1bb4a9b3e183af12225f56c27164c10d06223 vim +/best_div +334 drivers/clk/at91/clk-sam9x60-pll.c 324 325 static long sam9x60_div_pll_compute_div(struct sam9x60_pll_core *core, 326 unsigned long *parent_rate, 327 unsigned long rate) 328 { 329 const struct clk_pll_characteristics *characteristics = 330 core->characteristics; 331 struct clk_hw *parent = clk_hw_get_parent(&core->hw); 332 unsigned long tmp_rate, tmp_parent_rate, tmp_diff; 333 long best_diff = -1, best_rate = -EINVAL; 335 336 if (!rate) 337 return 0; 338 339 if (rate < characteristics->output[0].min || 340 rate > characteristics->output[0].max) 341 return -ERANGE; 342 343 for (divid = 1; divid < core->layout->div_mask; divid++) { 344 tmp_parent_rate = clk_hw_round_rate(parent, rate * divid); 345 if (!tmp_parent_rate) 346 continue; 347 348 tmp_rate = DIV_ROUND_CLOSEST_ULL(tmp_parent_rate, divid); 349 tmp_diff = abs(rate - tmp_rate); 350 351 if (best_diff < 0 || best_diff > tmp_diff) { 352 *parent_rate = tmp_parent_rate; 353 best_rate = tmp_rate; 354 best_diff = tmp_diff; 355 best_div = divid; 356 } 357 358 if (!best_diff) 359 break; 360 } 361 362 if (best_rate < characteristics->output[0].min || 363 best_rate > characteristics->output[0].max) 364 return -ERANGE; 365 366 return best_rate; 367 } 368 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org