Hi John, FYI, the error/warning still remains. tree: https://android.googlesource.com/kernel/common android12-5.10-2021-08 head: fe9069667a5af7b74caa501c945d7482d324e9e5 commit: 34ebaf13befc0cd9274a190affbeae8e94f16ced [5024/10760] ANDROID: drm: kirin: Introduce kirin960 config: arm64-randconfig-r015-20211012 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project adf55ac6657693f7bfbe3087b599b4031a765a44) 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 arm64 cross compiling tool for clang build # apt-get install binutils-aarch64-linux-gnu git remote add android-common https://android.googlesource.com/kernel/common git fetch --no-tags android-common android12-5.10-2021-08 git checkout 34ebaf13befc0cd9274a190affbeae8e94f16ced # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=arm64 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 >>): void dsi_set_output_client(struct drm_device *dev) ^ drivers/gpu/drm/hisilicon/kirin/kirin_drm_dsi.c:33:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void dsi_set_output_client(struct drm_device *dev) ^ static 1 warning generated. vim +/dsi_set_output_client +33 drivers/gpu/drm/hisilicon/kirin/kirin_drm_dsi.c 32 34 { 35 enum dsi_output_client client; 36 struct drm_connector *connector; 37 struct drm_encoder *encoder; 38 struct drm_connector_list_iter conn_iter; 39 struct dw_dsi *dsi; 40 41 mutex_lock(&dev->mode_config.mutex); 42 43 /* find dsi encoder */ 44 drm_for_each_encoder(encoder, dev) 45 if (encoder->encoder_type == DRM_MODE_ENCODER_DSI) 46 break; 47 dsi = encoder_to_dsi(encoder); 48 49 /* find HDMI connector */ 50 drm_connector_list_iter_begin(dev, &conn_iter); 51 drm_for_each_connector_iter(connector, &conn_iter) 52 if (connector->connector_type == DRM_MODE_CONNECTOR_HDMIA) 53 break; 54 drm_connector_list_iter_end(&conn_iter); 55 56 /* 57 * set the proper dsi output client 58 */ 59 client = connector->status == connector_status_connected ? OUT_HDMI : 60 OUT_PANEL; 61 if (client != dsi->cur_client) { 62 /* 63 * set the switch ic to select the HDMI or MIPI_DSI 64 */ 65 if (hisi_dsi_ops->version == KIRIN960_DSI) 66 gpiod_set_value_cansleep(dsi->gpio_mux, client); 67 68 dsi->cur_client = client; 69 /* let the userspace know panel connector status has changed */ 70 drm_sysfs_hotplug_event(dev); 71 DRM_INFO("client change to %s\n", 72 client == OUT_HDMI ? "HDMI" : "panel"); 73 } 74 75 mutex_unlock(&dev->mode_config.mutex); 76 } 77 EXPORT_SYMBOL_GPL(dsi_set_output_client); 78 /************************for the panel attach to dsi*****************************/ 79 static int dsi_connector_get_modes(struct drm_connector *connector) 80 { 81 struct dw_dsi *dsi = connector_to_dsi(connector); 82 83 return drm_panel_get_modes(dsi->panel, connector); 84 } 85 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org