[kbuild-all] [rcar:vsp1/v3u 13/23] drivers/media/v4l2-core/v4l2-async.c:777:5: warning: no previous prototype for function 'v4l2_async_pending_devices'

tree: https://git.kernel.org/pub/scm/linux/kernel/git/kbingham/rcar.git vsp1/v3u head: 178de9aa2b539612048856e54a292efda80f41c1 commit: fb68cc895bd671aa7d0b1cf67f873edb9b2a3f2e [13/23] WIP: Add async notifier state debug config: riscv-randconfig-r012-20210317 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 8ef111222a3dd12a9175f69c3bff598c46e8bdf7) 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 riscv cross compiling tool for clang build # apt-get install binutils-riscv64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/kbingham/rcar.git/commit/... git remote add rcar https://git.kernel.org/pub/scm/linux/kernel/git/kbingham/rcar.git git fetch --no-tags rcar vsp1/v3u git checkout fb68cc895bd671aa7d0b1cf67f873edb9b2a3f2e # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): drivers/media/v4l2-core/v4l2-async.c:786:23: warning: unused variable 'v4l2_dev' [-Wunused-variable] struct v4l2_device *v4l2_dev = ^ drivers/media/v4l2-core/v4l2-async.c:788:29: warning: unused variable 'asd' [-Wunused-variable] struct v4l2_async_subdev *asd; ^ int v4l2_async_pending_devices(void) ^ drivers/media/v4l2-core/v4l2-async.c:777:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int v4l2_async_pending_devices(void) ^ static 3 warnings generated. vim +/v4l2_async_pending_devices +777 drivers/media/v4l2-core/v4l2-async.c 775 776 778 { 779 struct v4l2_async_notifier *notifier; 780 struct v4l2_subdev *sd; 781 782 mutex_lock(&list_lock); 783 784 /* Report on pending async subdevices. */ 785 list_for_each_entry(notifier, &notifier_list, list) { 786 struct v4l2_device *v4l2_dev = 787 v4l2_async_notifier_find_v4l2_dev(notifier); 788 struct v4l2_async_subdev *asd; 789 790 if (list_empty(&notifier->waiting)) { 791 printk("notifier is not waiting..."); 792 continue; 793 } 794 795 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org