Hi Alice, FYI, the error/warning still remains. tree: https://github.com/Freescale/linux-fslc pr/502 head: f040ed8ce37b5dc2c7d94005a4788549dcb608d1 commit: 3bc399ee42d1bb2c1d442bb524711eda588f13ca [11426/15836] MLK-25423-2 firmware: imx: register i.MX8ULP SoC device config: arm-randconfig-c002-20211119 (attached as .config) 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 arm cross compiling tool for clang build # apt-get install binutils-arm-linux-gnueabi # https://github.com/Freescale/linux-fslc/commit/3bc399ee42d1bb2c1d442bb524... git remote add freescale-fslc https://github.com/Freescale/linux-fslc git fetch --no-tags freescale-fslc pr/502 git checkout 3bc399ee42d1bb2c1d442bb524711eda588f13ca # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=arm 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 >>): struct device *imx_soc_device_register(void) ^ drivers/firmware/imx/s400-api.c:161:1: note: declare 'static' if the function is not intended to be used outside of this translation unit struct device *imx_soc_device_register(void) ^ static 1 warning generated. vim +/imx_soc_device_register +161 drivers/firmware/imx/s400-api.c 160 162 { 163 struct soc_device_attribute *attr; 164 struct soc_device *dev; 165 u32 v[4]; 166 int err; 167 168 s400_api_export->tx_msg.header = 0x17970206; 169 s400_api_export->tx_msg.data[0] = 0x1; 170 err = imx_s400_api_call(s400_api_export, v); 171 if (err) 172 return NULL; 173 174 attr = kzalloc(sizeof(*attr), GFP_KERNEL); 175 if (!attr) 176 return NULL; 177 178 attr->family = kasprintf(GFP_KERNEL, "Freescale i.MX"); 179 attr->revision = kasprintf(GFP_KERNEL, "unknown"); 180 attr->serial_number = kasprintf(GFP_KERNEL, "%016llX", (u64)v[3] << 32 | v[0]); 181 attr->soc_id = kasprintf(GFP_KERNEL, "i.MX8ULP"); 182 183 dev = soc_device_register(attr); 184 if (IS_ERR(dev)) { 185 kfree(attr->soc_id); 186 kfree(attr->serial_number); 187 kfree(attr->revision); 188 kfree(attr->family); 189 kfree(attr); 190 return ERR_CAST(dev); 191 } 192 193 return soc_device_to_device(dev); 194 } 195 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org