tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 6145d80cfc62e3ed8f16ff584d6287e6d88b82b9 commit: 70cca14c2cb134fa578b45bbb7a133d39513cbad [10757/11059] drm/amd/display: Add MST capability to trigger_hotplug interface config: x86_64-randconfig-a013-20210408 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 56ea2e2fdd691136d5e6631fa0e447173694b82c) 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 x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commi... git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout 70cca14c2cb134fa578b45bbb7a133d39513cbad # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 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 >>): if (!(aconnector->port && &aconnector->mst_port->mst_mgr)) ~~ ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~ 1 warning generated. vim +3015 drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_debugfs.c 2981 2982 /* 2983 * Sets trigger hpd for MST topologies. 2984 * All connected connectors will be rediscovered and re started as needed if val of 1 is sent. 2985 * All topologies will be disconnected if val of 0 is set . 2986 * Usage to enable topologies: echo 1 > /sys/kernel/debug/dri/0/amdgpu_dm_trigger_hpd_mst 2987 * Usage to disable topologies: echo 0 > /sys/kernel/debug/dri/0/amdgpu_dm_trigger_hpd_mst 2988 */ 2989 static int trigger_hpd_mst_set(void *data, u64 val) 2990 { 2991 struct amdgpu_device *adev = data; 2992 struct drm_device *dev = adev_to_drm(adev); 2993 struct drm_connector_list_iter iter; 2994 struct amdgpu_dm_connector *aconnector; 2995 struct drm_connector *connector; 2996 struct dc_link *link = NULL; 2997 2998 if (val == 1) { 2999 drm_connector_list_iter_begin(dev, &iter); 3000 drm_for_each_connector_iter(connector, &iter) { 3001 aconnector = to_amdgpu_dm_connector(connector); 3002 if (aconnector->dc_link->type == dc_connection_mst_branch && 3003 aconnector->mst_mgr.aux) { 3004 dc_link_detect(aconnector->dc_link, DETECT_REASON_HPD); 3005 drm_dp_mst_topology_mgr_set_mst(&aconnector->mst_mgr, true); 3006 } 3007 } 3008 } else if (val == 0) { 3009 drm_connector_list_iter_begin(dev, &iter); 3010 drm_for_each_connector_iter(connector, &iter) { 3011 aconnector = to_amdgpu_dm_connector(connector); 3012 if (!aconnector->dc_link) 3013 continue; 3014 3016 continue; 3017 3018 link = aconnector->dc_link; 3019 dp_receiver_power_ctrl(link, false); 3020 drm_dp_mst_topology_mgr_set_mst(&aconnector->mst_port->mst_mgr, false); 3021 link->mst_stream_alloc_table.stream_count = 0; 3022 memset(link->mst_stream_alloc_table.stream_allocations, 0, 3023 sizeof(link->mst_stream_alloc_table.stream_allocations)); 3024 } 3025 } else { 3026 return 0; 3027 } 3028 drm_kms_helper_hotplug_event(dev); 3029 3030 return 0; 3031 } 3032 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org