Hi Jani, I love your patch! Perhaps something to improve: [auto build test WARNING on drm-intel/for-linux-next] [also build test WARNING on tegra-drm/drm/tegra/for-next drm-tip/drm-tip linus/master drm-exynos/exynos-drm-next v5.9-rc5 next-20200917] [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/Jani-Nikula/drm-dp-add-subheadin... base: git://anongit.freedesktop.org/drm-intel for-linux-next config: nds32-randconfig-p001-20200917 (attached as .config) compiler: nds32le-linux-gcc (GCC) 9.3.0 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 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=nds32 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 >>): In file included from drivers/gpu/drm/drm_crtc_helper_internal.h:31, from drivers/gpu/drm/drm_crtc_helper.c:51: 640 | # define DP_ADJUST_TX_FFE_PRESET_LANE0_MASK (0xf << 4) | include/drm/drm_dp_helper.h:638: note: this is the location of the previous definition 638 | # define DP_ADJUST_TX_FFE_PRESET_LANE0_MASK (0xf << 0) | 641 | # define DP_ADJUST_TX_FFE_PRESET_LANE0_SHIFT 4 | include/drm/drm_dp_helper.h:639: note: this is the location of the previous definition 639 | # define DP_ADJUST_TX_FFE_PRESET_LANE0_SHIFT 0 | -- In file included from include/drm/drm_dp_mst_helper.h:26, from drivers/gpu/drm/drm_dp_mst_topology.c:43: 640 | # define DP_ADJUST_TX_FFE_PRESET_LANE0_MASK (0xf << 4) | include/drm/drm_dp_helper.h:638: note: this is the location of the previous definition 638 | # define DP_ADJUST_TX_FFE_PRESET_LANE0_MASK (0xf << 0) | 641 | # define DP_ADJUST_TX_FFE_PRESET_LANE0_SHIFT 4 | include/drm/drm_dp_helper.h:639: note: this is the location of the previous definition 639 | # define DP_ADJUST_TX_FFE_PRESET_LANE0_SHIFT 0 | drivers/gpu/drm/drm_dp_mst_topology.c: In function 'drm_dp_send_query_stream_enc_status': drivers/gpu/drm/drm_dp_mst_topology.c:3261:6: warning: variable 'len' set but not used [-Wunused-but-set-variable] 3261 | int len, ret; | ^~~ -- In file included from drivers/gpu/drm/bridge/analogix/analogix_dp_core.h:13, from drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c:17: 640 | # define DP_ADJUST_TX_FFE_PRESET_LANE0_MASK (0xf << 4) | include/drm/drm_dp_helper.h:638: note: this is the location of the previous definition 638 | # define DP_ADJUST_TX_FFE_PRESET_LANE0_MASK (0xf << 0) | 641 | # define DP_ADJUST_TX_FFE_PRESET_LANE0_SHIFT 4 | include/drm/drm_dp_helper.h:639: note: this is the location of the previous definition 639 | # define DP_ADJUST_TX_FFE_PRESET_LANE0_SHIFT 0 | drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c:527:5: warning: no previous prototype for 'analogix_dp_start_aux_transaction' [-Wmissing-prototypes] 527 | int analogix_dp_start_aux_transaction(struct analogix_dp_device *dp) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c:571:5: warning: no previous prototype for 'analogix_dp_write_byte_to_dpcd' [-Wmissing-prototypes] 571 | int analogix_dp_write_byte_to_dpcd(struct analogix_dp_device *dp, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ # https://github.com/0day-ci/linux/commit/ee700fcadff2b9f1f941cd4af77242e51... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Jani-Nikula/drm-dp-add-subheadings-to-DPCD-address-definitions/20200917-185206 git checkout ee700fcadff2b9f1f941cd4af77242e51a139649 vim +/DP_ADJUST_TX_FFE_PRESET_LANE0_MASK +640 include/drm/drm_dp_helper.h 636 637 /* DP 2.0 128b/132b Link Layer */ 638 # define DP_ADJUST_TX_FFE_PRESET_LANE0_MASK (0xf << 0) 639 # define DP_ADJUST_TX_FFE_PRESET_LANE0_SHIFT 0 642 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org