Hi Maxime, 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 linus/master v5.12-rc3 next-20210319] [cannot apply to anholt/for-next] [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/Maxime-Ripard/drm-vc4-hdmi-Add-S... base: git://anongit.freedesktop.org/drm-intel for-linux-next config: arm-randconfig-r011-20210318 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project fcc1ce00931751ac02498986feb37744e9ace8de) 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 arm cross compiling tool for clang build # apt-get install binutils-arm-linux-gnueabi # https://github.com/0day-ci/linux/commit/0f45bf9bf8c92c481545659e0dc09a15d... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Maxime-Ripard/drm-vc4-hdmi-Add-Support-for-the-YUV-output/20210317-234605 git checkout 0f45bf9bf8c92c481545659e0dc09a15dbfcffb9 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang 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 >>): struct drm_encoder *vc4_get_connector_encoder(struct drm_connector *connector) ^ drivers/gpu/drm/vc4/vc4_crtc.c:258:1: note: declare 'static' if the function is not intended to be used outside of this translation unit struct drm_encoder *vc4_get_connector_encoder(struct drm_connector *connector) ^ static 1 warning generated. vim +/vc4_get_connector_encoder +258 drivers/gpu/drm/vc4/vc4_crtc.c 257 259 { 260 struct drm_encoder *encoder; 261 262 if (WARN_ON(hweight32(connector->possible_encoders) != 1)) 263 return NULL; 264 265 drm_connector_for_each_possible_encoder(connector, encoder) 266 return encoder; 267 268 return NULL; 269 } 270 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org