Hi Chris, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 115a54162a6c0d0ef2aef25ebd0b61fc5e179ebe commit: e9e40543ad5b38b848879768359fd13650529961 spi: Add generic SPI multiplexer date: 3 months ago config: x86_64-randconfig-r022-20200519 (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 135b877874fae96b4372c8a3fbfaa8ff44ff86e3) reproduce: 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 e9e40543ad5b38b848879768359fd13650529961 # 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: kbuild test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): drivers/mux/adgs1408.c:62:12: warning: cast to smaller integer type 'enum adgs1408_chip_id' from 'const void *' [-Wvoid-pointer-to-enum-cast] chip_id = (enum adgs1408_chip_id)of_device_get_match_data(dev); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ static const struct of_device_id adgs1408_of_match[] = { ^ 2 warnings generated. vim +/adgs1408_of_match +112 drivers/mux/adgs1408.c 8b9ce6954c05e3 Mircea Caprioru 2018-08-01 111 8b9ce6954c05e3 Mircea Caprioru 2018-08-01 @112 static const struct of_device_id adgs1408_of_match[] = { 8b9ce6954c05e3 Mircea Caprioru 2018-08-01 113 { .compatible = "adi,adgs1408", .data = (void *)ADGS1408, }, 8b9ce6954c05e3 Mircea Caprioru 2018-08-01 114 { .compatible = "adi,adgs1409", .data = (void *)ADGS1409, }, 8b9ce6954c05e3 Mircea Caprioru 2018-08-01 115 { } 8b9ce6954c05e3 Mircea Caprioru 2018-08-01 116 }; 8b9ce6954c05e3 Mircea Caprioru 2018-08-01 117 MODULE_DEVICE_TABLE(of, adgs1408_of_match); 8b9ce6954c05e3 Mircea Caprioru 2018-08-01 118 :::::: The code at line 112 was first introduced by commit :::::: 8b9ce6954c05e3e4115f54444c7eaf2aa2dd5e65 mux: adgs1408: new driver for Analog Devices ADGS1408/1409 mux :::::: TO: Mircea Caprioru <mircea.caprioru(a)analog.com&gt; :::::: CC: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org