Hi Sean, I love your patch! Yet something to improve: [auto build test ERROR on drm-tip/drm-tip] [also build test ERROR on v5.18-rc2 next-20220411] [cannot apply to drm/drm-next drm-intel/for-linux-next robh/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/intel-lab-lkp/linux/commits/Sean-Paul/drm-hdcp-Pull-HDCP-auth-exchange-check-into-helpers/20220412-045000 base: git://anongit.freedesktop.org/drm/drm-tip drm-tip config: mips-buildonly-randconfig-r001-20220411 (https://download.01.org/0day-ci/archive/20220412/202204120922.hnbHBMC7-lkp@xxxxxxxxx/config) compiler: mips-linux-gcc (GCC) 11.2.0 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 # https://github.com/intel-lab-lkp/linux/commit/7486d07edbd9a137420102bc24535c5d29c53c12 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Sean-Paul/drm-hdcp-Pull-HDCP-auth-exchange-check-into-helpers/20220412-045000 git checkout 7486d07edbd9a137420102bc24535c5d29c53c12 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=mips SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All errors (new ones prefixed by >>): mips-linux-ld: drivers/gpu/drm/drm_hdcp.o: in function `drm_hdcp_remote_dpcd_read': >> drm_hdcp.c:(.text+0x5e4): undefined reference to `drm_dp_dpcd_read' mips-linux-ld: drivers/gpu/drm/drm_hdcp.o: in function `drm_hdcp_remote_write': >> drm_hdcp.c:(.text+0xf48): undefined reference to `drm_dp_dpcd_write' -- 0-DAY CI Kernel Test Service https://01.org/lkp