Hi Zhi, 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 drm/drm-next next-20220325] [cannot apply to tegra-drm/drm/tegra/for-next airlied/drm-next v5.17] [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/Zhi-Wang/i915-gvt-Separate-the-MMIO-tracking-table-from-GVT-g/20220326-015627 base: git://anongit.freedesktop.org/drm-intel for-linux-next config: x86_64-randconfig-a011 (https://download.01.org/0day-ci/archive/20220326/202203260844.V9HDSROY-lkp@xxxxxxxxx/config) compiler: gcc-9 (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/8203f91121efdcc910bde0bc4fe5ea678bdaaa5b git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Zhi-Wang/i915-gvt-Separate-the-MMIO-tracking-table-from-GVT-g/20220326-015627 git checkout 8203f91121efdcc910bde0bc4fe5ea678bdaaa5b # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/gpu/drm/i915/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> drivers/gpu/drm/i915/gvt/handlers.c:74:6: warning: no previous prototype for 'intel_gvt_match_device' [-Wmissing-prototypes] 74 | bool intel_gvt_match_device(struct intel_gvt *gvt, | ^~~~~~~~~~~~~~~~~~~~~~ vim +/intel_gvt_match_device +74 drivers/gpu/drm/i915/gvt/handlers.c 12d14cc43b34706 Zhi Wang 2016-08-30 73 12d14cc43b34706 Zhi Wang 2016-08-30 @74 bool intel_gvt_match_device(struct intel_gvt *gvt, 12d14cc43b34706 Zhi Wang 2016-08-30 75 unsigned long device) 12d14cc43b34706 Zhi Wang 2016-08-30 76 { 12d14cc43b34706 Zhi Wang 2016-08-30 77 return intel_gvt_get_device_type(gvt) & device; 12d14cc43b34706 Zhi Wang 2016-08-30 78 } 12d14cc43b34706 Zhi Wang 2016-08-30 79 -- 0-DAY CI Kernel Test Service https://01.org/lkp