tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-next head: 4616dddcfaf75cfbfbff7ce8a468038c697444ce commit: 4a555f2b8d31d2dae523b56613a14360061e4c76 [10/16] usb: gadget: at91_udc: Convert to GPIO descriptors config: arm-randconfig-r016-20211121 (attached as .config) compiler: arm-linux-gnueabi-gcc (GCC) 11.2.0 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://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git/commit/?id... git remote add usb https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git git fetch --no-tags usb usb-next git checkout 4a555f2b8d31d2dae523b56613a14360061e4c76 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=arm 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 include/linux/kernel.h:20, from drivers/usb/gadget/udc/at91_udc.c:13: drivers/usb/gadget/udc/at91_udc.c: In function 'at91udc_probe': 5 | #define KERN_SOH "\001" /* ASCII Start Of Header */ | ^~~~~~ include/linux/printk.h:418:25: note: in definition of macro 'printk_index_wrap' 418 | _p_func(_fmt, ##__VA_ARGS__); \ | ^~~~ include/linux/printk.h:573:9: note: in expansion of macro 'printk' 573 | printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) | ^~~~~~ include/linux/kern_levels.h:15:25: note: in expansion of macro 'KERN_SOH' 15 | #define KERN_DEBUG KERN_SOH "7" /* debug-level messages */ | ^~~~~~~~ include/linux/printk.h:573:16: note: in expansion of macro 'KERN_DEBUG' 573 | printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) | ^~~~~~~~~~ drivers/usb/gadget/udc/at91_udc.h:174:33: note: in expansion of macro 'pr_debug' 174 | #define DBG(stuff...) pr_debug("udc: " stuff) | ^~~~~~~~ drivers/usb/gadget/udc/at91_udc.c:1897:33: note: in expansion of macro 'DBG' 1897 | DBG("request vbus irq %d failed\n", | ^~~ -- In file included from include/linux/kernel.h:20, from drivers/usb/gadget/udc/at91_udc.c:13: drivers/usb/gadget/udc/at91_udc.c: In function 'at91udc_probe': 5 | #define KERN_SOH "\001" /* ASCII Start Of Header */ | ^~~~~~ include/linux/printk.h:418:25: note: in definition of macro 'printk_index_wrap' 418 | _p_func(_fmt, ##__VA_ARGS__); \ | ^~~~ include/linux/printk.h:132:17: note: in expansion of macro 'printk' 132 | printk(fmt, ##__VA_ARGS__); \ | ^~~~~~ include/linux/printk.h:576:9: note: in expansion of macro 'no_printk' 576 | no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) | ^~~~~~~~~ include/linux/kern_levels.h:15:25: note: in expansion of macro 'KERN_SOH' 15 | #define KERN_DEBUG KERN_SOH "7" /* debug-level messages */ | ^~~~~~~~ include/linux/printk.h:576:19: note: in expansion of macro 'KERN_DEBUG' 576 | no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) | ^~~~~~~~~~ drivers/usb/gadget/udc/at91_udc.h:174:33: note: in expansion of macro 'pr_debug' 174 | #define DBG(stuff...) pr_debug("udc: " stuff) | ^~~~~~~~ drivers/usb/gadget/udc/at91_udc.c:1897:33: note: in expansion of macro 'DBG' 1897 | DBG("request vbus irq %d failed\n", | ^~~ vim +5 include/linux/kern_levels.h 314ba3520e513a Joe Perches 2012-07-30 4 04d2c8c83d0e3a Joe Perches 2012-07-30 @5 #define KERN_SOH "\001" /* ASCII Start Of Header */ 04d2c8c83d0e3a Joe Perches 2012-07-30 6 #define KERN_SOH_ASCII '\001' 04d2c8c83d0e3a Joe Perches 2012-07-30 7 :::::: The code at line 5 was first introduced by commit :::::: 04d2c8c83d0e3ac5f78aeede51babb3236200112 printk: convert the format for KERN_<LEVEL> to a 2 byte pattern :::::: TO: Joe Perches <joe(a)perches.com&gt; :::::: CC: Linus Torvalds <torvalds(a)linux-foundation.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org