Hi Yuti, FYI, the error/warning still remains. tree: git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git ti-rt-linux-5.4.y head: 99cf035411ae868ca277678d0902a4e4b7c48c63 commit: 027933539b12d9948f86bed77cb17767db19b343 [3577/6874] drm: bridge: cdns-mhdp: add j721e wrapper config: sh-randconfig-r011-20200515 (attached as .config) compiler: sh4-linux-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 git checkout 027933539b12d9948f86bed77cb17767db19b343 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day GCC_VERSION=9.3.0 make.cross ARCH=sh If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>, old ones prefixed by <<): In file included from drivers/gpu/drm/bridge/cdns-mhdp-core.c:39: 46 | { | ^ drivers/gpu/drm/bridge/cdns-mhdp-j721e.h:45:6: warning: 'cdns_mhdp_j721e_sst_enable' declared 'static' but never defined [-Wunused-function] 45 | void cdns_mhdp_j721e_sst_enable(struct cdns_mhdp_device *mhdp); | ^~~~~~~~~~~~~~~~~~~~~~~~~~ vim +46 drivers/gpu/drm/bridge/cdns-mhdp-j721e.h 43 44 static inline 45 void cdns_mhdp_j721e_sst_enable(struct cdns_mhdp_device *mhdp); 47 } 48 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org