Hi Tzu-En, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers-ne... master head: b28bd97c1c191ade3736b33f2b24e5b288b90ab4 commit: f745eb9ca5bf823bc5c0f82a434cefb41c57844e [40/69] rtw88: 8821c: Add 8821CE to Kconfig and Makefile config: x86_64-allyesconfig (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 02946de3802d3bc65bc9f2eb9b8d4969b5a7add8) 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 git checkout f745eb9ca5bf823bc5c0f82a434cefb41c57844e # 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 >>): static const u8 rtw8821c_get_swing_index(struct rtw_dev *rtwdev) ^~~~~~ 1 warning generated. vim +/const +71 drivers/net/wireless/realtek/rtw88/rtw8821c.c 3a4312828ce13e Tzu-En Huang 2020-06-03 70 3a4312828ce13e Tzu-En Huang 2020-06-03 @71 static const u8 rtw8821c_get_swing_index(struct rtw_dev *rtwdev) 3a4312828ce13e Tzu-En Huang 2020-06-03 72 { 3a4312828ce13e Tzu-En Huang 2020-06-03 73 u8 i = 0; 3a4312828ce13e Tzu-En Huang 2020-06-03 74 u32 swing, table_value; 3a4312828ce13e Tzu-En Huang 2020-06-03 75 3a4312828ce13e Tzu-En Huang 2020-06-03 76 swing = rtw_read32_mask(rtwdev, REG_TXSCALE_A, 0xffe00000); 3a4312828ce13e Tzu-En Huang 2020-06-03 77 for (i = 0; i < ARRAY_SIZE(rtw8821c_txscale_tbl); i++) { 3a4312828ce13e Tzu-En Huang 2020-06-03 78 table_value = rtw8821c_txscale_tbl[i]; 3a4312828ce13e Tzu-En Huang 2020-06-03 79 if (swing == table_value) 3a4312828ce13e Tzu-En Huang 2020-06-03 80 break; 3a4312828ce13e Tzu-En Huang 2020-06-03 81 } 3a4312828ce13e Tzu-En Huang 2020-06-03 82 3a4312828ce13e Tzu-En Huang 2020-06-03 83 return i; 3a4312828ce13e Tzu-En Huang 2020-06-03 84 } 3a4312828ce13e Tzu-En Huang 2020-06-03 85 :::::: The code at line 71 was first introduced by commit :::::: 3a4312828ce13e1645fd3af76e4314a2623b3361 rtw88: 8821c: add power tracking :::::: TO: Tzu-En Huang <tehuang(a)realtek.com&gt; :::::: CC: Kalle Valo <kvalo(a)codeaurora.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org