[xilinx-xlnx:xlnx_rebase_v5.15_LTS 622/1129] drivers/media/i2c/adv7511-v4l2.c:2245:21: warning: no previous prototype for function 'adv7511_subdev'

[kernel test robot]

tree:   https://github.com/Xilinx/linux-xlnx xlnx_rebase_v5.15_LTS
head:   3076249fc30bf463f8390f89009de928ad3e95ff
commit: 59e26517c7b77c4c82aad32cfac74ae39c32b76b [622/1129] drivers: media: Customized adv7511 for Xylon LogiCVC (deprecated)
config: arm-randconfig-r002-20220506 (https://download.01.org/0day-ci/archive/20220506/202205062304.jxNotrGO-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 5e004fb787698440a387750db7f8028e7cb14cfc)
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
        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # https://github.com/Xilinx/linux-xlnx/commit/59e26517c7b77c4c82aad32cfac74ae39c32b76b
        git remote add xilinx-xlnx https://github.com/Xilinx/linux-xlnx
        git fetch --no-tags xilinx-xlnx xlnx_rebase_v5.15_LTS
        git checkout 59e26517c7b77c4c82aad32cfac74ae39c32b76b
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash drivers/media/i2c/

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

All warnings (new ones prefixed by >>):

>> drivers/media/i2c/adv7511-v4l2.c:2245:21: warning: no previous prototype for function 'adv7511_subdev' [-Wmissing-prototypes]
   struct v4l2_subdev *adv7511_subdev(struct v4l2_subdev *sd)
                       ^
   drivers/media/i2c/adv7511-v4l2.c:2245:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   struct v4l2_subdev *adv7511_subdev(struct v4l2_subdev *sd)
   ^
   static 
   drivers/media/i2c/adv7511-v4l2.c:304:19: warning: unused function 'adv7511_cec_write_and_or' [-Wunused-function]
   static inline int adv7511_cec_write_and_or(struct v4l2_subdev *sd, u8 reg, u8 mask,
                     ^
   drivers/media/i2c/adv7511-v4l2.c:334:20: warning: unused function 'adv7511_pktmem_wr_and_or' [-Wunused-function]
   static inline void adv7511_pktmem_wr_and_or(struct v4l2_subdev *sd, u8 reg, u8 clr_mask, u8 val_mask)
                      ^
   3 warnings generated.


vim +/adv7511_subdev +2245 drivers/media/i2c/adv7511-v4l2.c

  2244	
> 2245	struct v4l2_subdev *adv7511_subdev(struct v4l2_subdev *sd)
  2246	{
  2247		static struct v4l2_subdev *subdev;
  2248	
  2249		if (sd)
  2250			subdev = sd;
  2251	
  2252		return subdev;
  2253	}
  2254	EXPORT_SYMBOL(adv7511_subdev);
  2255	

-- 
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https://01.org/lkp