Hi Miles, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on joro-iommu/next] [also build test WARNING on v5.18-rc3 next-20220422] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/intel-lab-lkp/linux/commits/Miles-Chen/iommu-mediatek-fix-NULL-pointer-dereference-when-printing-dev_name/20220423-070605 base: https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git next config: hexagon-randconfig-r041-20220422 (https://download.01.org/0day-ci/archive/20220423/202204231446.IYKdZ674-lkp@xxxxxxxxx/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 5bd87350a5ae429baf8f373cb226a57b62f87280) 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://github.com/intel-lab-lkp/linux/commit/85771767e503ca60069fe4e6ec2ddb80c7f9bafa git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Miles-Chen/iommu-mediatek-fix-NULL-pointer-dereference-when-printing-dev_name/20220423-070605 git checkout 85771767e503ca60069fe4e6ec2ddb80c7f9bafa # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash drivers/iommu/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> drivers/iommu/mtk_iommu.c:605:6: warning: variable 'larbdev' is uninitialized when used here [-Wuninitialized] if (larbdev) { ^~~~~~~ drivers/iommu/mtk_iommu.c:597:24: note: initialize the variable 'larbdev' to silence this warning struct device *larbdev; ^ = NULL 1 warning generated. vim +/larbdev +605 drivers/iommu/mtk_iommu.c 592 593 static void mtk_iommu_release_device(struct device *dev) 594 { 595 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); 596 struct mtk_iommu_data *data; 597 struct device *larbdev; 598 unsigned int larbid; 599 600 if (!fwspec || fwspec->ops != &mtk_iommu_ops) 601 return; 602 603 data = dev_iommu_priv_get(dev); 604 larbid = MTK_M4U_TO_LARB(fwspec->ids[0]); > 605 if (larbdev) { 606 larbdev = data->larb_imu[larbid].dev; 607 device_link_remove(dev, larbdev); 608 } 609 610 iommu_fwspec_free(dev); 611 } 612 -- 0-DAY CI Kernel Test Service https://01.org/lkp
