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(a)intel.com&gt; All errors (new ones prefixed by >>): 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 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@lists.01.org