Hi Tomi,

I love your patch! Yet something to improve:

[auto build test ERROR on media-tree/master]
[also build test ERROR on tegra/for-next v5.16-rc6 next-20211220]
[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/Tomi-Valkeinen/v4l-subdev-active-state/20211217-215244
base:   git://linuxtv.org/media_tree.git master
config: mips-loongson2k_defconfig (https://download.01.org/0day-ci/archive/20211221/202112210321.dlOWsxJG-lkp(a)intel.com/config)
compiler: mips64el-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/728c6f8f7c038fd0c851160b170cdc08f1999b38
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Tomi-Valkeinen/v4l-subdev-active-state/20211217-215244
        git checkout 728c6f8f7c038fd0c851160b170cdc08f1999b38
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=mips SHELL=/bin/bash drivers/media/v4l2-core/

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/media/v4l2-core/v4l2-subdev.c: In function 'v4l2_subdev_init_finalize':
>> drivers/media/v4l2-core/v4l2-subdev.c:951:17: error: implicit declaration of function '__v4l2_subdev_state_alloc' [-Werror=implicit-function-declaration]
     951 |         state = __v4l2_subdev_state_alloc(sd);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/media/v4l2-core/v4l2-subdev.c:951:15: warning: assignment to 'struct v4l2_subdev_state *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
     951 |         state = __v4l2_subdev_state_alloc(sd);
         |               ^
   drivers/media/v4l2-core/v4l2-subdev.c: In function 'v4l2_subdev_cleanup':
   drivers/media/v4l2-core/v4l2-subdev.c:963:9: error: implicit declaration of function '__v4l2_subdev_state_free' [-Werror=implicit-function-declaration]
     963 |         __v4l2_subdev_state_free(sd->active_state);
         |         ^~~~~~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +/__v4l2_subdev_state_alloc +951 drivers/media/v4l2-core/v4l2-subdev.c

   946	
   947	int v4l2_subdev_init_finalize(struct v4l2_subdev *sd)
   948	{
   949		struct v4l2_subdev_state *state;
   950	
 > 951		state = __v4l2_subdev_state_alloc(sd);
   952		if (IS_ERR(state))
   953			return PTR_ERR(state);
   954	
   955		sd->active_state = state;
   956	
   957		return 0;
   958	}
   959	EXPORT_SYMBOL_GPL(v4l2_subdev_init_finalize);
   960	

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