tree: https://github.com/Xilinx/linux-xlnx xlnx_rebase_v5.10 head: e14d4574ca81a569ee6d07e03271f2ae2dad38e4 commit: f6f032f82f0a13def702a0154df535db88f43391 [1756/1761] media: i2c: ap1302: Add a flag to check the streaming status config: s390-randconfig-r012-20210812 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 767496d19cb9a1fbba57ff08095faa161998ee36) 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/Xilinx/linux-xlnx/commit/f6f032f82f0a13def702a0154df53... git remote add xlnx https://github.com/Xilinx/linux-xlnx git fetch --no-tags xlnx xlnx_rebase_v5.10 git checkout f6f032f82f0a13def702a0154df535db88f43391 # 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 <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): 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:20:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \ ^ In file included from drivers/media/i2c/ap1302.c:15: 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/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/media/i2c/ap1302.c:15: 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/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/media/i2c/ap1302.c:15: 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/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/media/i2c/ap1302.c:15: 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/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); ~~~~~~~~~~ ^ if (enable == ap1302->streaming) ^~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/media/i2c/ap1302.c:1692:6: note: uninitialized use occurs here if (ret < 0) ^~~ drivers/media/i2c/ap1302.c:1676:2: note: remove the 'if' if its condition is always false if (enable == ap1302->streaming) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/media/i2c/ap1302.c:1672:9: note: initialize the variable 'ret' to silence this warning int ret; ^ = 0 21 warnings generated. vim +1676 drivers/media/i2c/ap1302.c 1668 1669 static int ap1302_s_stream(struct v4l2_subdev *sd, int enable) 1670 { 1671 struct ap1302_device *ap1302 = to_ap1302(sd); 1672 int ret; 1673 1674 mutex_lock(&ap1302->lock); 1675 1677 goto done; 1678 1679 if (enable) { 1680 ret = ap1302_configure(ap1302); 1681 if (ret < 0) 1682 goto done; 1683 1684 ret = ap1302_stall(ap1302, false); 1685 } else { 1686 ret = ap1302_stall(ap1302, true); 1687 } 1688 1689 done: 1690 mutex_unlock(&ap1302->lock); 1691 1692 if (ret < 0) 1693 dev_err(ap1302->dev, "Failed to %s stream: %d\n", 1694 enable ? "start" : "stop", ret); 1695 1696 return ret; 1697 } 1698 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org