Hi Jonathan, [FYI, it's a private test report for your RFC patch.] [auto build test ERROR on linus/master] [also build test ERROR on v5.12-rc2 next-20210310] [cannot apply to pci/next] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Jonathan-Cameron/PCI-Data-Object... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 05a59d79793d482f628a31753c671f2e92178a21 config: powerpc-randconfig-c003-20210310 (attached as .config) compiler: powerpc-linux-gcc (GCC) 9.3.0 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 # https://github.com/0day-ci/linux/commit/57ebd10b28d20aa89ddd013bdf52956d2... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Jonathan-Cameron/PCI-Data-Object-Exchange-support-CXL-CDAT/20210311-021048 git checkout 57ebd10b28d20aa89ddd013bdf52956d20011d63 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): powerpc-linux-ld: drivers/cxl/mem.o: in function `cdat_get_length': powerpc-linux-ld: drivers/cxl/mem.o: in function `cdat_dump': mem.c:(.text+0x314): undefined reference to `pcie_doe_exchange' powerpc-linux-ld: drivers/cxl/mem.o: in function `cdat_to_buffer': mem.c:(.text+0x16b8): undefined reference to `pcie_doe_exchange' powerpc-linux-ld: drivers/cxl/mem.o: in function `cxl_mem_create': --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org