tree: https://chromium.googlesource.com/chromiumos/third_party/kernel chromeos-5.4 head: 0c71e22c5eec0cd8f64cafe6b923f541210506d8 commit: 4cd31ff53f596bcdb903a7f59af6565b812d2cc9 [58/61] FROMLIST: drm/mediatek: add component POSTMASK config: arm64-randconfig-r023-20210209 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c9439ca36342fb6013187d0a69aef92736951476) 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 chrome-os https://chromium.googlesource.com/chromiumos/third_party/kernel git fetch --no-tags chrome-os chromeos-5.4 git checkout 4cd31ff53f596bcdb903a7f59af6565b812d2cc9 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross 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 mtk_postmask_config(struct device *dev, unsigned int w, ^ drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c:199:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void mtk_postmask_config(struct device *dev, unsigned int w, ^ static void mtk_postmask_start(struct device *dev) ^ drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c:211:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void mtk_postmask_start(struct device *dev) ^ static void mtk_postmask_stop(struct device *dev) ^ drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c:218:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void mtk_postmask_stop(struct device *dev) ^ static 3 warnings generated. vim +/mtk_postmask_config +199 drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c 198 200 unsigned int h, unsigned int vrefresh, 201 unsigned int bpc, struct cmdq_pkt *cmdq_pkt) 202 { 203 struct mtk_ddp_comp_dev *priv = dev_get_drvdata(dev); 204 205 mtk_ddp_write(cmdq_pkt, w << 16 | h, &priv->cmdq_reg, priv->regs, 206 DISP_POSTMASK_SIZE); 207 mtk_ddp_write(cmdq_pkt, POSTMASK_RELAY_MODE, &priv->cmdq_reg, 208 priv->regs, DISP_POSTMASK_CFG); 209 } 210 212 { 213 struct mtk_ddp_comp_dev *priv = dev_get_drvdata(dev); 214 215 writel(POSTMASK_EN, priv->regs + DISP_POSTMASK_EN); 216 } 217 219 { 220 struct mtk_ddp_comp_dev *priv = dev_get_drvdata(dev); 221 222 writel_relaxed(0x0, priv->regs + DISP_POSTMASK_EN); 223 } 224 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org