Hi Fangzhi, Thank you for the 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-exynos/exynos-drm-next tegra-drm/drm/tegra/for-next linus/master v5.14-rc7 next-20210827] [cannot apply to drm/drm-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/Fangzhi-Zuo/Update-128b-132b-MST-Slot-Information/20210828-082044 base: git://anongit.freedesktop.org/drm-intel for-linux-next config: parisc-randconfig-r002-20210827 (attached as .config) compiler: hppa-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/0day-ci/linux/commit/8232240b519fadd6ad9eb814925e513a15407474 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Fangzhi-Zuo/Update-128b-132b-MST-Slot-Information/20210828-082044 git checkout 8232240b519fadd6ad9eb814925e513a15407474 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=parisc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): >> drivers/gpu/drm/drm_dp_mst_topology.c:4512:6: warning: no previous prototype for 'drm_dp_mst_update_encoding_cap' [-Wmissing-prototypes] 4512 | void drm_dp_mst_update_encoding_cap(struct drm_dp_mst_topology_mgr *mgr, uint8_t link_encoding_cap) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ vim +/drm_dp_mst_update_encoding_cap +4512 drivers/gpu/drm/drm_dp_mst_topology.c 4511 > 4512 void drm_dp_mst_update_encoding_cap(struct drm_dp_mst_topology_mgr *mgr, uint8_t link_encoding_cap) 4513 { 4514 if (link_encoding_cap == DP_CAP_ANSI_128B132B) { 4515 mgr->total_avail_slots = 64; 4516 mgr->start_slot = 0; 4517 } 4518 DRM_DEBUG_KMS("%s encoding format determined\n", 4519 (link_encoding_cap == DP_CAP_ANSI_128B132B) ? "128b/132b" : "8b/10b"); 4520 } 4521 EXPORT_SYMBOL(drm_dp_mst_update_encoding_cap); 4522 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org