Hi chenxiang, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on pm/linux-next] [also build test WARNING on pavel-linux-leds/for-next v5.7-rc6 next-20200519] [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/chenxiang/base-power-sysfs-Remov... base: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next config: arm-eseries_pxa_defconfig (attached as .config) compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 reproduce: 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=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): In file included from drivers/base/power/sysfs.c:3: include/linux/device.h:132:26: warning: 'dev_attr_runtime_status' defined but not used [-Wunused-variable] 132 | struct device_attribute dev_attr_##_name = __ATTR_RO(_name) | ^~~~~~~~~ >> drivers/base/power/sysfs.c:177:8: note: in expansion of macro 'DEVICE_ATTR_RO' 177 | static DEVICE_ATTR_RO(runtime_status); | ^~~~~~~~~~~~~~ vim +/DEVICE_ATTR_RO +177 drivers/base/power/sysfs.c 0fcb4eef829449 Alan Stern 2010-07-08 176 47acbd77e6e481 Andy Shevchenko 2017-11-10 @177 static DEVICE_ATTR_RO(runtime_status); 15bcb91d7e607d Alan Stern 2010-09-25 178 :::::: The code at line 177 was first introduced by commit :::::: 47acbd77e6e481abf2f41d3a99cb3762f296b2e6 PM / sysfs: Convert to use DEVICE_ATTR_RO / DEVICE_ATTR_RW :::::: TO: Andy Shevchenko <andriy.shevchenko(a)linux.intel.com&gt; :::::: CC: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org