tree:   git://git.monstr.eu/linux-2.6-microblaze for-test
head:   21f70b89dfef52f69ce1413868950cf5baf3868d
commit: ec8cdd50aa613113bb1480b0b103f42eea3f25d9 [218/1134] drivers: media: Customized adv7511 for Xylon LogiCVC (deprecated)
config: x86_64-randconfig-a004-20201111 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 874b0a0b9db93f5d3350ffe6b5efda2d908415d0)
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 x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        git remote add monstr-microblaze git://git.monstr.eu/linux-2.6-microblaze
        git fetch --no-tags monstr-microblaze for-test
        git checkout ec8cdd50aa613113bb1480b0b103f42eea3f25d9
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

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/i2c/adv7511-v4l2.c:427:2: error: void function 'adv7511_set_rgb_quantization_mode' should not return a value [-Wreturn-type]
           return 0;
           ^      ~
   drivers/media/i2c/adv7511-v4l2.c:2251:21: 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:2251:1: 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 
   1 warning and 1 error generated.

vim +/adv7511_set_rgb_quantization_mode +427 drivers/media/i2c/adv7511-v4l2.c

   421	
   422	static void adv7511_set_rgb_quantization_mode(struct v4l2_subdev *sd, struct v4l2_ctrl *ctrl)
   423	{
   424		struct adv7511_state *state = get_adv7511_state(sd);
   425	
   426	#ifdef XYLON_LOGICVC_INTG
 > 427		return 0;
   428	#endif
   429	
   430		/* Only makes sense for RGB formats */
   431		if (state->fmt_code != MEDIA_BUS_FMT_RGB888_1X24) {
   432			/* so just keep quantization */
   433			adv7511_csc_rgb_full2limit(sd, false);
   434			return;
   435		}
   436	
   437		switch (ctrl->val) {
   438		case V4L2_DV_RGB_RANGE_AUTO:
   439			/* automatic */
   440			if (state->dv_timings.bt.flags & V4L2_DV_FL_IS_CE_VIDEO) {
   441				/* CE format, RGB limited range (16-235) */
   442				adv7511_csc_rgb_full2limit(sd, true);
   443			} else {
   444				/* not CE format, RGB full range (0-255) */
   445				adv7511_csc_rgb_full2limit(sd, false);
   446			}
   447			break;
   448		case V4L2_DV_RGB_RANGE_LIMITED:
   449			/* RGB limited range (16-235) */
   450			adv7511_csc_rgb_full2limit(sd, true);
   451			break;
   452		case V4L2_DV_RGB_RANGE_FULL:
   453			/* RGB full range (0-255) */
   454			adv7511_csc_rgb_full2limit(sd, false);
   455			break;
   456		}
   457	}
   458	

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