Hi Xiong, I love your patch! Perhaps something to improve: [auto build test WARNING on drm-intel/for-linux-next] [also build test WARNING on drm-tip/drm-tip v5.10 next-20201211] [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/Xiong-Zhang/drm-i915-Try-to-gues... base: git://anongit.freedesktop.org/drm-intel for-linux-next config: i386-randconfig-s002-20201214 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.3-184-g1b896707-dirty # https://github.com/0day-ci/linux/commit/718272991fa5c06a48629bce020ecfbde... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Xiong-Zhang/drm-i915-Try-to-guess-PCH-type-even-without-ISA-bridge/20201214-150157 git checkout 718272991fa5c06a48629bce020ecfbdea006f96 # save the attached .config to linux build tree make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; "sparse warnings: (new ones prefixed by >>)" Please review and possibly fold the followup patch. --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org