Hi Michael, I love your patch! Perhaps something to improve: [auto build test WARNING on net-next/master] [also build test WARNING on next-20201210] [cannot apply to net/master ipvs/master linus/master v5.10-rc7] [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/Michael-Grzeschik/microchip-add-... base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git af3f4a85d90218bb59315d591bd2bffa5e646466 config: riscv-randconfig-r003-20201210 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 1968804ac726e7674d5de22bc2204b45857da344) 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/db1f7322c8fa2c28587f13ab3eebbb6ee... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Michael-Grzeschik/microchip-add-support-for-ksz88x3-driver-family/20201207-205945 git checkout db1f7322c8fa2c28587f13ab3eebbb6ee02874b1 # 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 >>): ~~~~~~~~~~ ^ 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/net/dsa/microchip/ksz8795.c:11: In file included from include/linux/gpio.h:62: In file included from include/asm-generic/gpio.h:11: In file included from include/linux/gpio/driver.h:7: In file included from include/linux/irq.h:20: 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/net/dsa/microchip/ksz8795.c:11: In file included from include/linux/gpio.h:62: In file included from include/asm-generic/gpio.h:11: In file included from include/linux/gpio/driver.h:7: In file included from include/linux/irq.h:20: 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/net/dsa/microchip/ksz8795.c:11: In file included from include/linux/gpio.h:62: In file included from include/asm-generic/gpio.h:11: In file included from include/linux/gpio/driver.h:7: In file included from include/linux/irq.h:20: 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/net/dsa/microchip/ksz8795.c:11: In file included from include/linux/gpio.h:62: In file included from include/asm-generic/gpio.h:11: In file included from include/linux/gpio/driver.h:7: In file included from include/linux/irq.h:20: 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/net/dsa/microchip/ksz8795.c:11: In file included from include/linux/gpio.h:62: In file included from include/asm-generic/gpio.h:11: In file included from include/linux/gpio/driver.h:7: In file included from include/linux/irq.h:20: 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/net/dsa/microchip/ksz8795.c:11: In file included from include/linux/gpio.h:62: In file included from include/asm-generic/gpio.h:11: In file included from include/linux/gpio/driver.h:7: In file included from include/linux/irq.h:20: 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; ~~~~~~~~~~ ^ [DYNAMIC_MAC_ENTRIES] = 29, ^~ drivers/net/dsa/microchip/ksz8795.c:64:29: note: previous initialization is here [VLAN_TABLE_MEMBERSHIP] = 7, ^ 8 warnings generated. /tmp/ksz8795-ce9b6a.s: Assembler messages: /tmp/ksz8795-ce9b6a.s:183: Error: unrecognized opcode `zext.b a2,s9' /tmp/ksz8795-ce9b6a.s:447: Error: unrecognized opcode `zext.b a2,a1' /tmp/ksz8795-ce9b6a.s:454: Error: unrecognized opcode `zext.b a2,a0' /tmp/ksz8795-ce9b6a.s:521: Error: unrecognized opcode `zext.b a0,s3' /tmp/ksz8795-ce9b6a.s:555: Error: unrecognized opcode `zext.b s6,s3' /tmp/ksz8795-ce9b6a.s:568: Error: unrecognized opcode `zext.b s3,s1' /tmp/ksz8795-ce9b6a.s:635: Error: unrecognized opcode `zext.b a0,s3' /tmp/ksz8795-ce9b6a.s:654: Error: unrecognized opcode `zext.b a0,s3' /tmp/ksz8795-ce9b6a.s:737: Error: unrecognized opcode `zext.b s3,s3' /tmp/ksz8795-ce9b6a.s:753: Error: unrecognized opcode `zext.b s1,a1' /tmp/ksz8795-ce9b6a.s:794: Error: unrecognized opcode `zext.b s3,s3' /tmp/ksz8795-ce9b6a.s:836: Error: unrecognized opcode `zext.b s1,a1' /tmp/ksz8795-ce9b6a.s:880: Error: unrecognized opcode `zext.b s1,a1' /tmp/ksz8795-ce9b6a.s:1548: Error: unrecognized opcode `zext.b a2,a1' /tmp/ksz8795-ce9b6a.s:1572: Error: unrecognized opcode `zext.b a2,a1' /tmp/ksz8795-ce9b6a.s:1610: Error: unrecognized opcode `zext.b s3,a1' /tmp/ksz8795-ce9b6a.s:1648: Error: unrecognized opcode `zext.b a2,a0' /tmp/ksz8795-ce9b6a.s:1658: Error: unrecognized opcode `zext.b a2,a0' /tmp/ksz8795-ce9b6a.s:1665: Error: unrecognized opcode `zext.b a2,a0' /tmp/ksz8795-ce9b6a.s:1676: Error: unrecognized opcode `zext.b a2,a0' /tmp/ksz8795-ce9b6a.s:1687: Error: unrecognized opcode `zext.b a2,a0' /tmp/ksz8795-ce9b6a.s:2701: Error: unrecognized opcode `zext.b a2,s7' /tmp/ksz8795-ce9b6a.s:2868: Error: unrecognized opcode `zext.b a4,a4' /tmp/ksz8795-ce9b6a.s:2876: Error: unrecognized opcode `zext.b a1,a1' /tmp/ksz8795-ce9b6a.s:3027: Error: unrecognized opcode `zext.b a1,a1' /tmp/ksz8795-ce9b6a.s:3049: Error: unrecognized opcode `zext.b a2,a2' clang-12: error: assembler command failed with exit code 1 (use -v to see invocation) vim +69 drivers/net/dsa/microchip/ksz8795.c 62 63 static const u8 ksz8795_shifts[] = { 64 [VLAN_TABLE_MEMBERSHIP] = 7, 65 [VLAN_TABLE] = 16, 66 [STATIC_MAC_FWD_PORTS] = 16, 67 [STATIC_MAC_FID] = 24, 68 [DYNAMIC_MAC_ENTRIES_H] = 3, 70 [DYNAMIC_MAC_FID] = 16, 71 [DYNAMIC_MAC_TIMESTAMP] = 27, 72 [DYNAMIC_MAC_SRC_PORT] = 24, 73 }; 74 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org