tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: c2e7554e1b85935d962127efa3c2a76483b0b3b6 commit: 54d8454436a205682bd89d66d8d9eedbc8452d15 mmc: host: Enable compile testing of multiple drivers date: 2 months ago config: x86_64-randconfig-r002-20201119 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project b2613fb2f0f53691dd0211895afbb9413457fca7) 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/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 54d8454436a205682bd89d66d8d9eedbc8452d15 # 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 >>): drivers/mmc/host/sdhci-sprd.c:134:20: warning: unused function 'sdhci_sprd_writew' [-Wunused-function] static inline void sdhci_sprd_writew(struct sdhci_host *host, u16 val, int reg) ^ static const struct of_device_id sdhci_sprd_of_match[] = { ^ 2 warnings generated. vim +/sdhci_sprd_of_match +723 drivers/mmc/host/sdhci-sprd.c fb8bd90f83c4dd8 Chunyan Zhang 2018-08-30 722 fb8bd90f83c4dd8 Chunyan Zhang 2018-08-30 @723 static const struct of_device_id sdhci_sprd_of_match[] = { fb8bd90f83c4dd8 Chunyan Zhang 2018-08-30 724 { .compatible = "sprd,sdhci-r11", }, fb8bd90f83c4dd8 Chunyan Zhang 2018-08-30 725 { } fb8bd90f83c4dd8 Chunyan Zhang 2018-08-30 726 }; fb8bd90f83c4dd8 Chunyan Zhang 2018-08-30 727 MODULE_DEVICE_TABLE(of, sdhci_sprd_of_match); fb8bd90f83c4dd8 Chunyan Zhang 2018-08-30 728 :::::: The code at line 723 was first introduced by commit :::::: fb8bd90f83c4dd86bc7fdae406152d63c5852f92 mmc: sdhci-sprd: Add Spreadtrum's initial host controller :::::: TO: Chunyan Zhang <chunyan.zhang(a)unisoc.com&gt; :::::: CC: Ulf Hansson <ulf.hansson(a)linaro.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org