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@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/hisilicon/kirin/kirin_drm_dsi.c:33:6: warning: no previous prototype for function 'dsi_set_output_client' [-Wmissing-prototypes]
   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	
  > 33	void dsi_set_output_client(struct drm_device *dev)
    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(a)lists.01.org