Hi Damien, I love your patch! Perhaps something to improve: [auto build test WARNING on robh/for-next] [also build test WARNING on spi/for-next pza/reset/next v5.10-rc3] [cannot apply to linus/master next-20201113] [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/Damien-Le-Moal/RISC-V-Kendryte-K... base: https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next config: riscv-randconfig-r026-20201109 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 09ec07827b1128504457a93dee80b2ceee1af600) 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 riscv cross compiling tool for clang build # apt-get install binutils-riscv64-linux-gnu # https://github.com/0day-ci/linux/commit/b53c7c4d3b5b4658b4951955fd69c0ceb... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Damien-Le-Moal/RISC-V-Kendryte-K210-support-improvments/20201109-095540 git checkout b53c7c4d3b5b4658b4951955fd69c0ceb4bfac4d # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv 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/pinctrl/pinctrl-k210.c:6: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:149: include/asm-generic/io.h:556:9: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return inb(addr); ^~~~~~~~~ arch/riscv/include/asm/io.h:55:76: note: expanded from macro 'inb' #define inb(c) ({ u8 __v; __io_pbr(); __v = readb_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:87:48: note: expanded from macro 'readb_cpu' #define readb_cpu(c) ({ u8 __r = __raw_readb(c); __r; }) ^ In file included from drivers/pinctrl/pinctrl-k210.c:6: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:149: include/asm-generic/io.h:564:9: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return inw(addr); ^~~~~~~~~ arch/riscv/include/asm/io.h:56:76: note: expanded from macro 'inw' #define inw(c) ({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:88:76: note: expanded from macro 'readw_cpu' #define readw_cpu(c) ({ u16 __r = le16_to_cpu((__force __le16)__raw_readw(c)); __r; }) ^ include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) ^ In file included from drivers/pinctrl/pinctrl-k210.c:6: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:149: include/asm-generic/io.h:572:9: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return inl(addr); ^~~~~~~~~ arch/riscv/include/asm/io.h:57:76: note: expanded from macro 'inl' #define inl(c) ({ u32 __v; __io_pbr(); __v = readl_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:89:76: note: expanded from macro 'readl_cpu' #define readl_cpu(c) ({ u32 __r = le32_to_cpu((__force __le32)__raw_readl(c)); __r; }) ^ include/uapi/linux/byteorder/little_endian.h:34:51: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) ^ In file included from drivers/pinctrl/pinctrl-k210.c:6: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:149: include/asm-generic/io.h:580:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] outb(value, addr); ^~~~~~~~~~~~~~~~~ arch/riscv/include/asm/io.h:59:68: note: expanded from macro 'outb' #define outb(v,c) ({ __io_pbw(); writeb_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:91:52: note: expanded from macro 'writeb_cpu' #define writeb_cpu(v, c) ((void)__raw_writeb((v), (c))) ^ In file included from drivers/pinctrl/pinctrl-k210.c:6: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:149: include/asm-generic/io.h:588:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] outw(value, addr); ^~~~~~~~~~~~~~~~~ arch/riscv/include/asm/io.h:60:68: note: expanded from macro 'outw' #define outw(v,c) ({ __io_pbw(); writew_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:92:76: note: expanded from macro 'writew_cpu' #define writew_cpu(v, c) ((void)__raw_writew((__force u16)cpu_to_le16(v), (c))) ^ In file included from drivers/pinctrl/pinctrl-k210.c:6: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:149: include/asm-generic/io.h:596:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] outl(value, addr); ^~~~~~~~~~~~~~~~~ arch/riscv/include/asm/io.h:61:68: note: expanded from macro 'outl' #define outl(v,c) ({ __io_pbw(); writel_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:93:76: note: expanded from macro 'writel_cpu' #define writel_cpu(v, c) ((void)__raw_writel((__force u32)cpu_to_le32(v), (c))) ^ In file included from drivers/pinctrl/pinctrl-k210.c:6: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:149: include/asm-generic/io.h:1005:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port; ~~~~~~~~~~ ^ drivers/pinctrl/pinctrl-k210.c:135:2: error: initializer element is not a compile-time constant K210_PIN_NAME(0), K210_PIN_NAME(1), K210_PIN_NAME(2), ^~~~~~~~~~~~~~~~ drivers/pinctrl/pinctrl-k210.c:132:45: note: expanded from macro 'K210_PIN_NAME' #define K210_PIN_NAME(i) [i] = k210_pins[i].name ~~~~~~~~~~~~~^~~~ int k210_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev, ^ drivers/pinctrl/pinctrl-k210.c:848:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int k210_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev, ^ static 8 warnings and 1 error generated. vim +/k210_pinctrl_dt_node_to_map +848 drivers/pinctrl/pinctrl-k210.c 847 849 struct device_node *np_config, 850 struct pinctrl_map **map, unsigned int *num_maps) 851 { 852 unsigned int reserved_maps; 853 struct device_node *np; 854 int ret; 855 856 reserved_maps = 0; 857 *map = NULL; 858 *num_maps = 0; 859 860 ret = k210_pinctrl_dt_subnode_to_map(pctldev, np_config, map, 861 &reserved_maps, num_maps); 862 if (ret < 0) 863 goto err; 864 865 for_each_available_child_of_node(np_config, np) { 866 ret = k210_pinctrl_dt_subnode_to_map(pctldev, np, map, 867 &reserved_maps, num_maps); 868 if (ret < 0) 869 goto err; 870 } 871 return 0; 872 873 err: 874 pinctrl_utils_free_map(pctldev, *map, *num_maps); 875 return ret; 876 } 877 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org