Hi Marvin, I love your patch! Perhaps something to improve: [auto build test WARNING on media-tree/master] [also build test WARNING on linus/master next-20221220] [cannot apply to robh/for-next v6.1] [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/Marvin-Lin/Support-Nuvoton-NPCM-Video-Capture-Encode-Engine/20221220-175013 base: git://linuxtv.org/media_tree.git master patch link: https://lore.kernel.org/r/20221220094055.3011916-8-milkfafa%40gmail.com patch subject: [PATCH v9 7/7] media: nuvoton: Add driver for NPCM video capture and encode engine config: hexagon-allmodconfig compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project f5700e7b69048de958172fb513b336564e7f8709) 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 # https://github.com/intel-lab-lkp/linux/commit/e37f65b3251b5953005dcdcf39d153c87b40c083 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Marvin-Lin/Support-Nuvoton-NPCM-Video-Capture-Encode-Engine/20221220-175013 git checkout e37f65b3251b5953005dcdcf39d153c87b40c083 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon olddefconfig COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash drivers/media/platform/nuvoton/ drivers/media/platform/verisilicon/ drivers/net/ethernet/marvell/prestera/ drivers/pwm/ kernel/trace/ sound/soc/qcom/qdsp6/ sound/usb/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot All warnings (new ones prefixed by >>): In file included from drivers/media/platform/nuvoton/npcm-video.c:15: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/hexagon/include/asm/io.h:334: include/asm-generic/io.h:547:31: 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:560:61: 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/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) ^ In file included from drivers/media/platform/nuvoton/npcm-video.c:15: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/hexagon/include/asm/io.h:334: include/asm-generic/io.h:573:61: 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/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) ^ In file included from drivers/media/platform/nuvoton/npcm-video.c:15: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/hexagon/include/asm/io.h:334: include/asm-generic/io.h:584:33: 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:594:59: 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:604:59: 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); ~~~~~~~~~~ ^ >> drivers/media/platform/nuvoton/npcm-video.c:556:6: warning: variable 'count' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] if (video->list && video->rect) { ^~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/media/platform/nuvoton/npcm-video.c:567:9: note: uninitialized use occurs here return count; ^~~~~ drivers/media/platform/nuvoton/npcm-video.c:556:2: note: remove the 'if' if its condition is always true if (video->list && video->rect) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> drivers/media/platform/nuvoton/npcm-video.c:556:6: warning: variable 'count' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized] if (video->list && video->rect) { ^~~~~~~~~~~ drivers/media/platform/nuvoton/npcm-video.c:567:9: note: uninitialized use occurs here return count; ^~~~~ drivers/media/platform/nuvoton/npcm-video.c:556:6: note: remove the '&&' if its condition is always true if (video->list && video->rect) { ^~~~~~~~~~~~~~ drivers/media/platform/nuvoton/npcm-video.c:554:20: note: initialize the variable 'count' to silence this warning unsigned int count; ^ = 0 >> drivers/media/platform/nuvoton/npcm-video.c:1017:13: warning: variable 'baseptr' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] } else if (of_device_is_compatible(video->dev->of_node, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/media/platform/nuvoton/npcm-video.c:1045:9: note: uninitialized use occurs here memset(baseptr, 0, GMMAP_LENGTH); ^~~~~~~ drivers/media/platform/nuvoton/npcm-video.c:1017:9: note: remove the 'if' if its condition is always true } else if (of_device_is_compatible(video->dev->of_node, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/media/platform/nuvoton/npcm-video.c:993:23: note: initialize the variable 'baseptr' to silence this warning void __iomem *baseptr; ^ = NULL 9 warnings generated. vim +556 drivers/media/platform/nuvoton/npcm-video.c 549 550 static unsigned int npcm_video_get_rect_count(struct npcm_video *video) 551 { 552 struct list_head *head, *pos, *nx; 553 struct rect_list *tmp; 554 unsigned int count; 555 > 556 if (video->list && video->rect) { 557 count = video->rect[video->vb_index]; 558 head = &video->list[video->vb_index]; 559 560 list_for_each_safe(pos, nx, head) { 561 tmp = list_entry(pos, struct rect_list, list); 562 list_del(&tmp->list); 563 kfree(tmp); 564 } 565 } 566 567 return count; 568 } 569 -- 0-DAY CI Kernel Test Service https://01.org/lkp