tree: https://github.com/jimc/linux.git dd-drm-next head: 7c9c791fee34dc8f3ef72a288efd6de7b48d5fb2 commit: fde769af5cc2d7134533d623f5808d114843263e [6/8] drm_print: add choice to use dynamic debug in drm-debug config: i386-randconfig-c001-20210816 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/jimc/linux/commit/fde769af5cc2d7134533d623f5808d114843... git remote add jimc https://github.com/jimc/linux.git git fetch --no-tags jimc dd-drm-next git checkout fde769af5cc2d7134533d623f5808d114843263e # save the attached .config to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash 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 >>): In file included from include/linux/printk.h:456, from include/asm-generic/bug.h:22, from arch/x86/include/asm/bug.h:84, from include/linux/bug.h:5, from include/linux/io.h:11, from drivers/gpu/drm/drm_print.c:30: 267 | module_param_cbd(fsname, &param_ops_dyndbg, &var, 0644, \ | ^ drivers/gpu/drm/drm_print.c:60:1: note: in expansion of macro 'DEFINE_DYNAMIC_DEBUG_CATEGORIES' 60 | DEFINE_DYNAMIC_DEBUG_CATEGORIES(debug, __drm_debug, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/dynamic_debug.h:265:37: warning: 'dyndbg_cats_debug' defined but not used [-Wunused-const-variable=] 265 | static const struct dyndbg_bitdesc dyndbg_cats_##fsname[] = \ | ^~~~~~~~~~~~ drivers/gpu/drm/drm_print.c:60:1: note: in expansion of macro 'DEFINE_DYNAMIC_DEBUG_CATEGORIES' 60 | DEFINE_DYNAMIC_DEBUG_CATEGORIES(debug, __drm_debug, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ vim +267 include/linux/dynamic_debug.h ec8e20fb31430e Jim Cromie 2021-07-28 245 ec8e20fb31430e Jim Cromie 2021-07-28 246 #if defined(CONFIG_DYNAMIC_DEBUG) || \ ec8e20fb31430e Jim Cromie 2021-07-28 247 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) ec8e20fb31430e Jim Cromie 2021-07-28 248 /** ec8e20fb31430e Jim Cromie 2021-07-28 249 * DEFINE_DYNAMIC_DEBUG_CATEGORIES() - define debug categories, bitmap, sysfs-knob ec8e20fb31430e Jim Cromie 2021-07-28 250 * @fsname: parameter basename under /sys ec8e20fb31430e Jim Cromie 2021-07-28 251 * @var: C-identifier holding state ec8e20fb31430e Jim Cromie 2021-07-28 252 * @_desc: string summarizing the controls provided ec8e20fb31430e Jim Cromie 2021-07-28 253 * @...: list of struct dyndbg_bitdesc initializations ec8e20fb31430e Jim Cromie 2021-07-28 254 * ec8e20fb31430e Jim Cromie 2021-07-28 255 * Defines /sys/modules/$modname/parameters/@fsname, and @bit_descs, ec8e20fb31430e Jim Cromie 2021-07-28 256 * which maps bits 0-N to categories of pr_debugs to be controlled. ec8e20fb31430e Jim Cromie 2021-07-28 257 * This is effectively write only, because controlled callsites can be ec8e20fb31430e Jim Cromie 2021-07-28 258 * further modified via >control. ec8e20fb31430e Jim Cromie 2021-07-28 259 * ec8e20fb31430e Jim Cromie 2021-07-28 260 * Also calls MODULE_PARM_DESC(fsname, _desc), with the intent to ec8e20fb31430e Jim Cromie 2021-07-28 261 * generate the bit_legend and apply it to the given bit_descs ec8e20fb31430e Jim Cromie 2021-07-28 262 */ ec8e20fb31430e Jim Cromie 2021-07-28 263 #define DEFINE_DYNAMIC_DEBUG_CATEGORIES(fsname, var, _desc, ...) \ ec8e20fb31430e Jim Cromie 2021-07-28 264 MODULE_PARM_DESC(fsname, _desc); \ ec8e20fb31430e Jim Cromie 2021-07-28 265 static const struct dyndbg_bitdesc dyndbg_cats_##fsname[] = \ ec8e20fb31430e Jim Cromie 2021-07-28 266 { __VA_ARGS__, { NULL, NULL } }; \ ec8e20fb31430e Jim Cromie 2021-07-28 @267 module_param_cbd(fsname, &param_ops_dyndbg, &var, 0644, \ ec8e20fb31430e Jim Cromie 2021-07-28 268 &dyndbg_cats_##fsname) ec8e20fb31430e Jim Cromie 2021-07-28 269 :::::: The code at line 267 was first introduced by commit :::::: ec8e20fb31430e6a18affbddaac7fbe29255ffaa dyndbg: add DEFINE_DYNAMIC_DEBUG_CATEGORIES and callbacks :::::: TO: Jim Cromie <jim.cromie(a)gmail.com&gt; :::::: CC: Jim Cromie <jim.cromie(a)gmail.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org