Hi Radhey, FYI, the error/warning still remains. tree: https://github.com/Xilinx/linux-xlnx master head: 163a7d26208a6794f595eeee3d54787df5e903d4 commit: c2644339194bd7be4ce6023d72f5e7a03f55ef6b [10742/12287] drivers: media: Customized adv7511 for Xylon LogiCVC (deprecated) config: powerpc64-randconfig-r032-20210622 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project b3634d3e88b7f26534a5057bff182b7dced584fc) 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 powerpc64 cross compiling tool for clang build # apt-get install binutils-powerpc64-linux-gnu # https://github.com/Xilinx/linux-xlnx/commit/c2644339194bd7be4ce6023d72f5e... git remote add xlnx https://github.com/Xilinx/linux-xlnx git fetch --no-tags xlnx master git checkout c2644339194bd7be4ce6023d72f5e7a03f55ef6b # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): __do_insb ^ arch/powerpc/include/asm/io.h:541:56: note: expanded from macro '__do_insb' #define __do_insb(p, b, n) readsb((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from drivers/media/i2c/adv7511-v4l2.c:20: 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/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:45:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(insw, (unsigned long p, void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:185:1: note: expanded from here __do_insw ^ arch/powerpc/include/asm/io.h:542:56: note: expanded from macro '__do_insw' #define __do_insw(p, b, n) readsw((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from drivers/media/i2c/adv7511-v4l2.c:20: 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/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:47:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(insl, (unsigned long p, void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:189:1: note: expanded from here __do_insl ^ arch/powerpc/include/asm/io.h:543:56: note: expanded from macro '__do_insl' #define __do_insl(p, b, n) readsl((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from drivers/media/i2c/adv7511-v4l2.c:20: 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/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:49:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsb, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:193:1: note: expanded from here __do_outsb ^ arch/powerpc/include/asm/io.h:544:58: note: expanded from macro '__do_outsb' #define __do_outsb(p, b, n) writesb((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from drivers/media/i2c/adv7511-v4l2.c:20: 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/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:51:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsw, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:197:1: note: expanded from here __do_outsw ^ arch/powerpc/include/asm/io.h:545:58: note: expanded from macro '__do_outsw' #define __do_outsw(p, b, n) writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from drivers/media/i2c/adv7511-v4l2.c:20: 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/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:53:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:201:1: note: expanded from here __do_outsl ^ arch/powerpc/include/asm/io.h:546:58: note: expanded from macro '__do_outsl' #define __do_outsl(p, b, n) writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ return 0; ^ ~ drivers/media/i2c/adv7511-v4l2.c:2251:21: warning: no previous prototype for function 'adv7511_subdev' [-Wmissing-prototypes] struct v4l2_subdev *adv7511_subdev(struct v4l2_subdev *sd) ^ drivers/media/i2c/adv7511-v4l2.c:2251:1: note: declare 'static' if the function is not intended to be used outside of this translation unit struct v4l2_subdev *adv7511_subdev(struct v4l2_subdev *sd) ^ static 8 warnings and 1 error generated. vim +/adv7511_set_rgb_quantization_mode +427 drivers/media/i2c/adv7511-v4l2.c 421 422 static void adv7511_set_rgb_quantization_mode(struct v4l2_subdev *sd, struct v4l2_ctrl *ctrl) 423 { 424 struct adv7511_state *state = get_adv7511_state(sd); 425 426 #ifdef XYLON_LOGICVC_INTG 428 #endif 429 430 /* Only makes sense for RGB formats */ 431 if (state->fmt_code != MEDIA_BUS_FMT_RGB888_1X24) { 432 /* so just keep quantization */ 433 adv7511_csc_rgb_full2limit(sd, false); 434 return; 435 } 436 437 switch (ctrl->val) { 438 case V4L2_DV_RGB_RANGE_AUTO: 439 /* automatic */ 440 if (state->dv_timings.bt.flags & V4L2_DV_FL_IS_CE_VIDEO) { 441 /* CE format, RGB limited range (16-235) */ 442 adv7511_csc_rgb_full2limit(sd, true); 443 } else { 444 /* not CE format, RGB full range (0-255) */ 445 adv7511_csc_rgb_full2limit(sd, false); 446 } 447 break; 448 case V4L2_DV_RGB_RANGE_LIMITED: 449 /* RGB limited range (16-235) */ 450 adv7511_csc_rgb_full2limit(sd, true); 451 break; 452 case V4L2_DV_RGB_RANGE_FULL: 453 /* RGB full range (0-255) */ 454 adv7511_csc_rgb_full2limit(sd, false); 455 break; 456 } 457 } 458 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org