tree: https://github.com/frank-w/BPI-R2-4.14 5.14-hdmilarb2 head: 77b4c96140f9bec5bb54fc804b401af1c9a6b4b5 commit: f94886349fc7e9a28901486218351f8e31fe950f [37/48] add debug in fwspec_set config: x86_64-randconfig-r013-20210718 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 5d5b08761f944d5b9822d582378333cc4b36a0a7) 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 # https://github.com/frank-w/BPI-R2-4.14/commit/f94886349fc7e9a289014862183... git remote add frank-w-bpi-r2-4.14 https://github.com/frank-w/BPI-R2-4.14 git fetch --no-tags frank-w-bpi-r2-4.14 5.14-hdmilarb2 git checkout f94886349fc7e9a28901486218351f8e31fe950f # 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 warnings (new ones prefixed by >>): In file included from drivers/gpu/drm/exynos/exynos_drm_dma.c:9: dev_err(dev,"%s:%d 0x%08x",__FUNCTION__,__LINE__,(unsigned int)fwspec); ^~~~~~~~~~~~~~~~~~~~ include/linux/dev_printk.h:112:32: note: expanded from macro 'dev_err' _dev_err(dev, dev_fmt(fmt), ##__VA_ARGS__) ^~~~~~~~~~~ drivers/gpu/drm/exynos/exynos_drm_dma.c:121:19: warning: variable 'mapping' is uninitialized when used here [-Wuninitialized] priv->mapping = mapping; ^~~~~~~ drivers/gpu/drm/exynos/exynos_drm_dma.c:111:16: note: initialize the variable 'mapping' to silence this warning void *mapping; ^ = NULL 2 warnings generated. vim +576 include/linux/iommu.h 571 572 static inline void dev_iommu_fwspec_set(struct device *dev, 573 struct iommu_fwspec *fwspec) 574 { 575 dev->iommu->fwspec = fwspec; 577 dump_stack(); 578 } 579 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org