Hi Thierry, I love your patch! Perhaps something to improve: [auto build test WARNING on linus/master] [also build test WARNING on v5.8-rc1 next-20200615] [cannot apply to pwm/for-next] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Thierry-Reding/pwm-Miscellaneous... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git b3a9e3b9622ae10064826dccb4f7a52bd88c7407 config: h8300-randconfig-r004-20200615 (attached as .config) compiler: h8300-linux-gcc (GCC) 9.3.0 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 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=h8300 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 >>, old ones prefixed by <<): In file included from include/linux/printk.h:404, from include/linux/kernel.h:15, from include/asm-generic/bug.h:19, from arch/h8300/include/asm/bug.h:8, from include/linux/bug.h:5, from include/linux/thread_info.h:12, from include/asm-generic/current.h:5, from ./arch/h8300/include/generated/asm/current.h:1, from include/linux/sched.h:12, from include/linux/ratelimit.h:6, from include/linux/dev_printk.h:16, from include/linux/device.h:15, from include/linux/backlight.h:12, from drivers/video/fbdev/ssd1307fb.c:8: drivers/video/fbdev/ssd1307fb.c: In function 'ssd1307fb_init': 315 | dev_dbg(&par->client->dev, "Using PWM%d with a %lluns period.n", | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/dynamic_debug.h:125:15: note: in definition of macro '__dynamic_func_call' 125 | func(&id, ##__VA_ARGS__); | ^~~~~~~~~~~ include/linux/dynamic_debug.h:157:2: note: in expansion of macro '_dynamic_func_call' 157 | _dynamic_func_call(fmt,__dynamic_dev_dbg, | ^~~~~~~~~~~~~~~~~~ include/linux/dev_printk.h:115:2: note: in expansion of macro 'dynamic_dev_dbg' 115 | dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__) | ^~~~~~~~~~~~~~~ include/linux/dev_printk.h:115:23: note: in expansion of macro 'dev_fmt' 115 | dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__) | ^~~~~~~ drivers/video/fbdev/ssd1307fb.c:315:3: note: in expansion of macro 'dev_dbg' 315 | dev_dbg(&par->client->dev, "Using PWM%d with a %lluns period.n", | ^~~~~~~ drivers/video/fbdev/ssd1307fb.c:315:53: note: format string is defined here 315 | dev_dbg(&par->client->dev, "Using PWM%d with a %lluns period.n", | ~~~^ | | | long long unsigned int | %u vim +315 drivers/video/fbdev/ssd1307fb.c 294 295 static int ssd1307fb_init(struct ssd1307fb_par *par) 296 { 297 struct pwm_state pwmstate; 298 int ret; 299 u32 precharge, dclk, com_invdir, compins; 300 301 if (par->device_info->need_pwm) { 302 par->pwm = pwm_get(&par->client->dev, NULL); 303 if (IS_ERR(par->pwm)) { 304 dev_err(&par->client->dev, "Could not get PWM from device tree!\n"); 305 return PTR_ERR(par->pwm); 306 } 307 308 pwm_init_state(par->pwm, &pwmstate); 309 pwm_set_relative_duty_cycle(&pwmstate, 50, 100); 310 pwm_apply_state(par->pwm, &pwmstate); 311 312 /* Enable the PWM */ 313 pwm_enable(par->pwm); 314 316 par->pwm->pwm, pwm_get_period(par->pwm)); 317 } 318 319 /* Set initial contrast */ 320 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST); 321 if (ret < 0) 322 return ret; 323 324 ret = ssd1307fb_write_cmd(par->client, par->contrast); 325 if (ret < 0) 326 return ret; 327 328 /* Set segment re-map */ 329 if (par->seg_remap) { 330 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON); 331 if (ret < 0) 332 return ret; 333 } 334 335 /* Set COM direction */ 336 com_invdir = 0xc0 | par->com_invdir << 3; 337 ret = ssd1307fb_write_cmd(par->client, com_invdir); 338 if (ret < 0) 339 return ret; 340 341 /* Set multiplex ratio value */ 342 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_MULTIPLEX_RATIO); 343 if (ret < 0) 344 return ret; 345 346 ret = ssd1307fb_write_cmd(par->client, par->height - 1); 347 if (ret < 0) 348 return ret; 349 350 /* set display offset value */ 351 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_DISPLAY_OFFSET); 352 if (ret < 0) 353 return ret; 354 355 ret = ssd1307fb_write_cmd(par->client, par->com_offset); 356 if (ret < 0) 357 return ret; 358 359 /* Set clock frequency */ 360 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_CLOCK_FREQ); 361 if (ret < 0) 362 return ret; 363 364 dclk = ((par->dclk_div - 1) & 0xf) | (par->dclk_frq & 0xf) << 4; 365 ret = ssd1307fb_write_cmd(par->client, dclk); 366 if (ret < 0) 367 return ret; 368 369 /* Set Set Area Color Mode ON/OFF & Low Power Display Mode */ 370 if (par->area_color_enable || par->low_power) { 371 u32 mode; 372 373 ret = ssd1307fb_write_cmd(par->client, 374 SSD1307FB_SET_AREA_COLOR_MODE); 375 if (ret < 0) 376 return ret; 377 378 mode = (par->area_color_enable ? 0x30 : 0) | 379 (par->low_power ? 5 : 0); 380 ret = ssd1307fb_write_cmd(par->client, mode); 381 if (ret < 0) 382 return ret; 383 } 384 385 /* Set precharge period in number of ticks from the internal clock */ 386 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PRECHARGE_PERIOD); 387 if (ret < 0) 388 return ret; 389 390 precharge = (par->prechargep1 & 0xf) | (par->prechargep2 & 0xf) << 4; 391 ret = ssd1307fb_write_cmd(par->client, precharge); 392 if (ret < 0) 393 return ret; 394 395 /* Set COM pins configuration */ 396 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COM_PINS_CONFIG); 397 if (ret < 0) 398 return ret; 399 400 compins = 0x02 | !par->com_seq << 4 | par->com_lrremap << 5; 401 ret = ssd1307fb_write_cmd(par->client, compins); 402 if (ret < 0) 403 return ret; 404 405 /* Set VCOMH */ 406 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_VCOMH); 407 if (ret < 0) 408 return ret; 409 410 ret = ssd1307fb_write_cmd(par->client, par->vcomh); 411 if (ret < 0) 412 return ret; 413 414 /* Turn on the DC-DC Charge Pump */ 415 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP); 416 if (ret < 0) 417 return ret; 418 419 ret = ssd1307fb_write_cmd(par->client, 420 BIT(4) | (par->device_info->need_chargepump ? BIT(2) : 0)); 421 if (ret < 0) 422 return ret; 423 424 /* Set lookup table */ 425 if (par->lookup_table_set) { 426 int i; 427 428 ret = ssd1307fb_write_cmd(par->client, 429 SSD1307FB_SET_LOOKUP_TABLE); 430 if (ret < 0) 431 return ret; 432 433 for (i = 0; i < ARRAY_SIZE(par->lookup_table); ++i) { 434 u8 val = par->lookup_table[i]; 435 436 if (val < 31 || val > 63) 437 dev_warn(&par->client->dev, 438 "lookup table index %d value out of range 31 <= %d <= 63\n", 439 i, val); 440 ret = ssd1307fb_write_cmd(par->client, val); 441 if (ret < 0) 442 return ret; 443 } 444 } 445 446 /* Switch to horizontal addressing mode */ 447 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE); 448 if (ret < 0) 449 return ret; 450 451 ret = ssd1307fb_write_cmd(par->client, 452 SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL); 453 if (ret < 0) 454 return ret; 455 456 /* Set column range */ 457 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE); 458 if (ret < 0) 459 return ret; 460 461 ret = ssd1307fb_write_cmd(par->client, 0x0); 462 if (ret < 0) 463 return ret; 464 465 ret = ssd1307fb_write_cmd(par->client, par->width - 1); 466 if (ret < 0) 467 return ret; 468 469 /* Set page range */ 470 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE); 471 if (ret < 0) 472 return ret; 473 474 ret = ssd1307fb_write_cmd(par->client, par->page_offset); 475 if (ret < 0) 476 return ret; 477 478 ret = ssd1307fb_write_cmd(par->client, 479 par->page_offset + 480 DIV_ROUND_UP(par->height, 8) - 1); 481 if (ret < 0) 482 return ret; 483 484 /* Clear the screen */ 485 ssd1307fb_update_display(par); 486 487 /* Turn on the display */ 488 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON); 489 if (ret < 0) 490 return ret; 491 492 return 0; 493 } 494 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org