Hi Erling, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on media-tree/master] [also build test WARNING on linus/master v5.19] [cannot apply to next-20220728] [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#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Erling-Ljunggren/Add-the-cat24c208-EDID-EEPROM-driver-new-EDID-capability/20220728-194524 base: git://linuxtv.org/media_tree.git master config: s390-randconfig-c005-20220802 (https://download.01.org/0day-ci/archive/20220803/202208030925.bp514QvB-lkp@xxxxxxxxx/config) compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 52cd00cabf479aa7eb6dbb063b7ba41ea57bce9e) 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 s390 cross compiling tool for clang build # apt-get install binutils-s390x-linux-gnu # https://github.com/intel-lab-lkp/linux/commit/94ba9bb463937ad05b92c6be56a552894b386774 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Erling-Ljunggren/Add-the-cat24c208-EDID-EEPROM-driver-new-EDID-capability/20220728-194524 git checkout 94ba9bb463937ad05b92c6be56a552894b386774 # 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=s390 SHELL=/bin/bash drivers/gpu/drm/ drivers/media/i2c/ If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): In file included from drivers/media/i2c/cat24c208.c:19: In file included from include/linux/regmap.h:20: In file included from include/linux/iopoll.h:14: In file included from include/linux/io.h:13: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __raw_readb(PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x)) ^ include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16' #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x)) ^ In file included from drivers/media/i2c/cat24c208.c:19: In file included from include/linux/regmap.h:20: In file included from include/linux/iopoll.h:14: In file included from include/linux/io.h:13: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32' #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x)) ^ In file included from drivers/media/i2c/cat24c208.c:19: In file included from include/linux/regmap.h:20: In file included from include/linux/iopoll.h:14: In file included from include/linux/io.h:13: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writeb(value, PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ >> drivers/media/i2c/cat24c208.c:407:34: warning: unused variable 'cat24c208_of_match' [-Wunused-const-variable] static const struct of_device_id cat24c208_of_match[] = { ^ 13 warnings generated. Kconfig warnings: (for reference only) WARNING: unmet direct dependencies detected for DRM_DP_AUX_BUS Depends on [n]: HAS_IOMEM [=y] && DRM [=y] && OF [=n] Selected by [y]: - DRM_MSM [=y] && HAS_IOMEM [=y] && DRM [=y] && (ARCH_QCOM || SOC_IMX5 || COMPILE_TEST [=y]) && COMMON_CLK [=y] && IOMMU_SUPPORT [=y] && (QCOM_OCMEM [=n] || QCOM_OCMEM [=n]=n) && (QCOM_LLCC [=y] || QCOM_LLCC [=y]=n) && (QCOM_COMMAND_DB [=n] || QCOM_COMMAND_DB [=n]=n) vim +/cat24c208_of_match +407 drivers/media/i2c/cat24c208.c 406 > 407 static const struct of_device_id cat24c208_of_match[] = { 408 { .compatible = "onnn,cat24c208"}, 409 {} 410 }; 411 MODULE_DEVICE_TABLE(of, cat24c208_of_match); 412 -- 0-DAY CI Kernel Test Service https://01.org/lkp