Hi Kenneth, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on linux/master] [also build test WARNING on linus/master v5.9-rc1 next-20200819] [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] url: https://github.com/0day-ci/linux/commits/Kenneth-Chan/add-support-for-bat... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git bcf876870b95592b52519ed4aafcf9d95999bc9c config: x86_64-randconfig-a014-20200819 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project b34b1e38381fa4d1b1d9751a6b5233b68e734cfe) 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 x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 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 >>): if (val >= 0 || val <= 255) { ~~~~~~~~~^~~~~~~~~~~~~ drivers/platform/x86/panasonic-laptop.c:697:15: warning: overlapping comparisons always evaluate to true [-Wtautological-overlap-compare] if (val >= 0 || val <= 255) { ~~~~~~~~~^~~~~~~~~~~~~ drivers/platform/x86/panasonic-laptop.c:728:15: warning: overlapping comparisons always evaluate to true [-Wtautological-overlap-compare] if (val >= 0 || val <= 255) { ~~~~~~~~~^~~~~~~~~~~~~ 3 warnings generated. # https://github.com/0day-ci/linux/commit/1f9eb2351cf22424f1ca39f5068c51fe7... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Kenneth-Chan/add-support-for-battery-charging-threshold-mute-correctly-save-ac-dc-brightness-to-hardware-registers/20200819-020600 git checkout 1f9eb2351cf22424f1ca39f5068c51fe74189aba vim +667 drivers/platform/x86/panasonic-laptop.c 656 657 static ssize_t ac_brightness_store(struct device *dev, struct device_attribute *attr, 658 const char *buf, size_t count) 659 { 660 struct acpi_device *acpi = to_acpi_device(dev); 661 struct pcc_acpi *pcc = acpi_driver_data(acpi); 662 int err, val; 663 664 err = kstrtoint(buf, 0, &val); 665 if (err) 666 return err; 668 acpi_pcc_write_sset(pcc, SINF_AC_CUR_BRIGHT, val); 669 pcc->ac_brightness = val; 670 } 671 672 return count; 673 } 674 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org