Hi Douglas,

kernel test robot noticed the following build warnings:

[auto build test WARNING on robh/for-next]
[also build test WARNING on hid/for-next drm-misc/drm-misc-next linus/master v6.4-rc3 next-20230523]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Douglas-Anderson/dt-bindings-HID-i2c-hid-Add-panel-property-to-i2c-hid-backed-panels/20230524-034323
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
patch link:    https://lore.kernel.org/r/20230523122802.7.Ib1a98309c455cd7e26b931c69993d4fba33bbe15%40changeid
patch subject: [PATCH 7/9] HID: i2c-hid: Support being a panel follower
config: m68k-allyesconfig
compiler: m68k-linux-gcc (GCC) 12.1.0
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/intel-lab-lkp/linux/commit/fff5c7d6358fe0a778218b49582351e53040595d
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Douglas-Anderson/dt-bindings-HID-i2c-hid-Add-panel-property-to-i2c-hid-backed-panels/20230524-034323
        git checkout fff5c7d6358fe0a778218b49582351e53040595d
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash drivers/hid/i2c-hid/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202305240845.bJhmT3Im-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/hid/i2c-hid/i2c-hid-core.c:1011:5: warning: no previous prototype for 'i2c_hid_core_initial_power_up' [-Wmissing-prototypes]
    1011 | int i2c_hid_core_initial_power_up(struct i2c_hid *ihid)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/hid/i2c-hid/i2c-hid-core.c:1065:5: warning: no previous prototype for 'i2c_hid_core_panel_prepared' [-Wmissing-prototypes]
    1065 | int i2c_hid_core_panel_prepared(struct drm_panel_follower *follower)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/hid/i2c-hid/i2c-hid-core.c:1081:5: warning: no previous prototype for 'i2c_hid_core_panel_unpreparing' [-Wmissing-prototypes]
    1081 | int i2c_hid_core_panel_unpreparing(struct drm_panel_follower *follower)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/i2c_hid_core_panel_prepared +1065 drivers/hid/i2c-hid/i2c-hid-core.c

  1064	
> 1065	int i2c_hid_core_panel_prepared(struct drm_panel_follower *follower)
  1066	{
  1067		struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
  1068		struct hid_device *hid = ihid->hid;
  1069	
  1070		/*
  1071		 * hid->version is set on the first power up. If it's still zero then
  1072		 * this is the first power on so we should perform initial power up
  1073		 * steps.
  1074		 */
  1075		if (!hid->version)
  1076			return i2c_hid_core_initial_power_up(ihid);
  1077	
  1078		return i2c_hid_core_resume(ihid);
  1079	}
  1080	
> 1081	int i2c_hid_core_panel_unpreparing(struct drm_panel_follower *follower)
  1082	{
  1083		struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
  1084	
  1085		return i2c_hid_core_suspend(ihid);
  1086	}
  1087	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki