tree:   https://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl.git pending
head:   fa809cc6feedcd2575b63def7135dfaf066266bb
commit: cd744dacded6bd5e81d214737c8244e7873b81ba [37/38] tools/testing/cxl: Introduce a mock memory device + driver
config: xtensa-randconfig-r004-20210814 (attached as .config)
compiler: xtensa-linux-gcc (GCC) 11.2.0
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://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl.git/commit/?id=cd744dacded6bd5e81d214737c8244e7873b81ba
        git remote add cxl-cxl https://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl.git
        git fetch --no-tags cxl-cxl pending
        git checkout cd744dacded6bd5e81d214737c8244e7873b81ba
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=xtensa 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/cxl/core/pmem.c:42:12: warning: no previous prototype for 'match_nvdimm_bridge' [-Wmissing-prototypes]
      42 | __weak int match_nvdimm_bridge(struct device *dev, const void *data)
         |            ^~~~~~~~~~~~~~~~~~~
   In file included from drivers/cxl/cxlmem.h:5,
                    from drivers/cxl/core/pmem.c:7:
   include/uapi/linux/cxl_mem.h:53:3: warning: 'cxl_command_names' defined but not used [-Wunused-const-variable=]
      53 | } cxl_command_names[] = { CXL_CMDS };
         |   ^~~~~~~~~~~~~~~~~


vim +/match_nvdimm_bridge +42 drivers/cxl/core/pmem.c

    41	
  > 42	__weak int match_nvdimm_bridge(struct device *dev, const void *data)
    43	{
    44		return dev->type == &cxl_nvdimm_bridge_type;
    45	}
    46	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org