Hi Adrien, I love your patch! Perhaps something to improve: [auto build test WARNING on robh/for-next] [also build test WARNING on linus/master v5.10-rc7] [cannot apply to regulator/for-next next-20201207] [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/0day-ci/linux/commits/Adrien-Grassein/dt-bindings-regulator-Add-pf8x00-regulator/20201206-083433 base: https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next config: s390-randconfig-r036-20201207 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project a2f922140f5380571fb74179f2bf622b3b925697) 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/0day-ci/linux/commit/efbdd07e33c1265802f429333ea350f206b26406 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Adrien-Grassein/dt-bindings-regulator-Add-pf8x00-regulator/20201206-083433 git checkout efbdd07e33c1265802f429333ea350f206b26406 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=s390 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): In file included from include/linux/swap.h:9: In file included from include/linux/memcontrol.h:22: In file included from include/linux/writeback.h:14: In file included from include/linux/blk-cgroup.h:23: In file included from include/linux/blkdev.h:26: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:80: 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:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' ___constant_swab32(x) : \ ^ include/uapi/linux/swab.h:21:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \ ^ In file included from drivers/regulator/pf8x00-regulator.c:15: In file included from include/linux/regulator/driver.h:18: In file included from include/linux/regulator/consumer.h:35: In file included from include/linux/suspend.h:5: In file included from include/linux/swap.h:9: In file included from include/linux/memcontrol.h:22: In file included from include/linux/writeback.h:14: In file included from include/linux/blk-cgroup.h:23: In file included from include/linux/blkdev.h:26: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:80: 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:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' ___constant_swab32(x) : \ ^ include/uapi/linux/swab.h:22:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0xff000000UL) >> 24))) ^ In file included from drivers/regulator/pf8x00-regulator.c:15: In file included from include/linux/regulator/driver.h:18: In file included from include/linux/regulator/consumer.h:35: In file included from include/linux/suspend.h:5: In file included from include/linux/swap.h:9: In file included from include/linux/memcontrol.h:22: In file included from include/linux/writeback.h:14: In file included from include/linux/blk-cgroup.h:23: In file included from include/linux/blkdev.h:26: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:80: 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:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:120:12: note: expanded from macro '__swab32' __fswab32(x)) ^ In file included from drivers/regulator/pf8x00-regulator.c:15: In file included from include/linux/regulator/driver.h:18: In file included from include/linux/regulator/consumer.h:35: In file included from include/linux/suspend.h:5: In file included from include/linux/swap.h:9: In file included from include/linux/memcontrol.h:22: In file included from include/linux/writeback.h:14: In file included from include/linux/blk-cgroup.h:23: In file included from include/linux/blkdev.h:26: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:80: 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/regulator/pf8x00-regulator.c:263:23: warning: no previous prototype for function 'get_id_name' [-Wmissing-prototypes] const struct id_name *get_id_name(enum chips id) ^ drivers/regulator/pf8x00-regulator.c:263:7: note: declare 'static' if the function is not intended to be used outside of this translation unit const struct id_name *get_id_name(enum chips id) ^ static drivers/regulator/pf8x00-regulator.c:831:12: warning: unused function 'pf8x_suspend' [-Wunused-function] static int pf8x_suspend(struct device *dev) ^ drivers/regulator/pf8x00-regulator.c:836:12: warning: unused function 'pf8x_resume' [-Wunused-function] static int pf8x_resume(struct device *dev) ^ 23 warnings generated. vim +/get_id_name +263 drivers/regulator/pf8x00-regulator.c 262 > 263 const struct id_name *get_id_name(enum chips id) 264 { 265 const struct id_name *p = id_list; 266 267 while (p->id) { 268 if (p->id == id) 269 break; 270 p++; 271 } 272 return p; 273 } 274 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org