Hi Dave, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 5833291ab6de9c3e2374336b51c814e515e8f3a5 commit: 970eae15600a883e4ad27dd0757b18871cc983ab BackMerge tag 'v5.15-rc7' into drm-next date: 2 weeks ago config: arc-allyesconfig (attached as .config) compiler: arceb-elf-gcc (GCC) 11.2.0 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://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=970eae15600a883e4ad27dd0757b18871cc983ab git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 970eae15600a883e4ad27dd0757b18871cc983ab # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=arc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All errors (new ones prefixed by >>): >> drivers/gpu/drm/msm/adreno/a6xx_gpu.c:1643:6: error: no previous prototype for 'a6xx_gpu_set_freq' [-Werror=missing-prototypes] 1643 | void a6xx_gpu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp) | ^~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors vim +/a6xx_gpu_set_freq +1643 drivers/gpu/drm/msm/adreno/a6xx_gpu.c a2c3c0a54d4ccc Sharat Masetty 2018-10-04 1642 f6f59072e82190 Rob Clark 2021-09-27 @1643 void a6xx_gpu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp) f6f59072e82190 Rob Clark 2021-09-27 1644 { f6f59072e82190 Rob Clark 2021-09-27 1645 struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu); f6f59072e82190 Rob Clark 2021-09-27 1646 struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu); f6f59072e82190 Rob Clark 2021-09-27 1647 f6f59072e82190 Rob Clark 2021-09-27 1648 mutex_lock(&a6xx_gpu->gmu.lock); f6f59072e82190 Rob Clark 2021-09-27 1649 a6xx_gmu_set_freq(gpu, opp); f6f59072e82190 Rob Clark 2021-09-27 1650 mutex_unlock(&a6xx_gpu->gmu.lock); f6f59072e82190 Rob Clark 2021-09-27 1651 } f6f59072e82190 Rob Clark 2021-09-27 1652 :::::: The code at line 1643 was first introduced by commit :::::: f6f59072e821901d96c791864a07d57d8ec8d312 drm/msm/a6xx: Serialize GMU communication :::::: TO: Rob Clark :::::: CC: Rob Clark --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org