Hi Vladimir,

[FYI, it's a private test report for your RFC patch.]
[auto build test ERROR on net/master]

url:    https://github.com/0day-ci/linux/commits/Vladimir-Oltean/Make-DSA-switch-drivers-compatible-with-masters-which-unregister-on-shutdown/20210912-201056
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git f11ee2ad25b22c2ee587045dd6999434375532f7
config: xtensa-allyesconfig (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://github.com/0day-ci/linux/commit/535bb691a9ce71ade9ad1ce5a5fdae8c2fd46e27
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Vladimir-Oltean/Make-DSA-switch-drivers-compatible-with-masters-which-unregister-on-shutdown/20210912-201056
        git checkout 535bb691a9ce71ade9ad1ce5a5fdae8c2fd46e27
        # 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 errors (new ones prefixed by >>):

   drivers/net/dsa/b53/b53_mmap.c: In function 'b53_mmap_shutdown':
   drivers/net/dsa/b53/b53_mmap.c:332:1: error: no return statement in function returning non-void [-Werror=return-type]
     332 | }
         | ^
   drivers/net/dsa/b53/b53_mmap.c: At top level:
>> drivers/net/dsa/b53/b53_mmap.c:346:21: error: initialization of 'void (*)(struct platform_device *)' from incompatible pointer type 'int (*)(struct platform_device *)' [-Werror=incompatible-pointer-types]
     346 |         .shutdown = b53_mmap_shutdown,
         |                     ^~~~~~~~~~~~~~~~~
   drivers/net/dsa/b53/b53_mmap.c:346:21: note: (near initialization for 'b53_mmap_driver.shutdown')
   cc1: all warnings being treated as errors


vim +346 drivers/net/dsa/b53/b53_mmap.c

   342	
   343	static struct platform_driver b53_mmap_driver = {
   344		.probe = b53_mmap_probe,
   345		.remove = b53_mmap_remove,
 > 346		.shutdown = b53_mmap_shutdown,
   347		.driver = {
   348			.name = "b53-switch",
   349			.of_match_table = b53_mmap_of_table,
   350		},
   351	};
   352	

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