Hi Dan,

I love your patch! Yet something to improve:

[auto build test ERROR on a38fd8748464831584a19438cbb3082b5a2dab15]

url:    https://github.com/0day-ci/linux/commits/Dan-Williams/CXL-Port-Enumeration/20210402-025333
base:   a38fd8748464831584a19438cbb3082b5a2dab15
config: ia64-randconfig-r016-20210401 (attached as .config)
compiler: ia64-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/84c25f52c3c7f8f20988e98eb9947c4eace11927
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Dan-Williams/CXL-Port-Enumeration/20210402-025333
        git checkout 84c25f52c3c7f8f20988e98eb9947c4eace11927
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=ia64 

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

All errors (new ones prefixed by >>):

   In file included from drivers/cxl/core.c:7:
>> drivers/cxl/cxl.h:84:15: error: field 'range' has incomplete type
      84 |  struct range range;
         |               ^~~~~
   drivers/cxl/core.c: In function 'devm_cxl_add_root':
>> drivers/cxl/core.c:343:8: error: implicit declaration of function 'range_len' [-Werror=implicit-function-declaration]
     343 |   if (!range_len(&space->range))
         |        ^~~~~~~~~
   drivers/cxl/core.c: In function 'end_show':
   drivers/cxl/core.c:56:1: error: control reaches end of non-void function [-Werror=return-type]
      56 | }
         | ^
   drivers/cxl/core.c: In function 'start_show':
   drivers/cxl/core.c:47:1: error: control reaches end of non-void function [-Werror=return-type]
      47 | }
         | ^
   cc1: some warnings being treated as errors
--
   In file included from drivers/cxl/acpi.c:8:
>> drivers/cxl/cxl.h:84:15: error: field 'range' has incomplete type
      84 |  struct range range;
         |               ^~~~~


vim +/range +84 drivers/cxl/cxl.h

    82	
    83	struct cxl_address_space {
  > 84		struct range range;
    85		int interleave_size;
    86		unsigned long flags;
    87		unsigned long targets;
    88	};
    89	

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