Re: [PATCH] HID: generic: add LampArray support via hid-lamparray helper
From: kernel test robot
Date: Thu Feb 19 2026 - 15:28:55 EST
Hi Tim,
kernel test robot noticed the following build errors:
[auto build test ERROR on hid/for-next]
[also build test ERROR on linus/master v6.19 next-20260219]
[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/Tim-Guttzeit/HID-generic-add-LampArray-support-via-hid-lamparray-helper/20260219-211040
base: https://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git for-next
patch link: https://lore.kernel.org/r/20260219130217.2042972-1-tgu%40tuxedocomputers.com
patch subject: [PATCH] HID: generic: add LampArray support via hid-lamparray helper
config: x86_64-rhel-9.4 (https://download.01.org/0day-ci/archive/20260219/202602192131.Q9y8Kqvt-lkp@xxxxxxxxx/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260219/202602192131.Q9y8Kqvt-lkp@xxxxxxxxx/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202602192131.Q9y8Kqvt-lkp@xxxxxxxxx/
All errors (new ones prefixed by >>):
ld: vmlinux.o: in function `lamparray_led_brightness_set':
>> drivers/hid/hid-lamparray.c:449:(.text+0xcb5bbd): undefined reference to `led_mc_calc_color_components'
ld: vmlinux.o: in function `lamparray_register_led':
drivers/hid/hid-lamparray.c:585:(.text+0xcb5db3): undefined reference to `led_mc_calc_color_components'
ld: vmlinux.o: in function `led_classdev_multicolor_register':
>> include/linux/led-class-multicolor.h:70:(.text+0xcb5dd9): undefined reference to `led_classdev_multicolor_register_ext'
ld: vmlinux.o: in function `lamparray_unregister_led':
>> drivers/hid/hid-lamparray.c:615:(.text+0xcb60eb): undefined reference to `led_classdev_multicolor_unregister'
>> ld: drivers/hid/hid-lamparray.c:615:(.text+0xcb620b): undefined reference to `led_classdev_multicolor_unregister'
ld: drivers/hid/hid-lamparray.c:615:(.text+0xcb636d): undefined reference to `led_classdev_multicolor_unregister'
vim +449 drivers/hid/hid-lamparray.c
434
435 static int lamparray_led_brightness_set(struct led_classdev *cdev,
436 enum led_brightness brightness)
437 {
438 struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
439 struct lamparray_device *ldev =
440 container_of(mc, struct lamparray_device, mc_cdev);
441 struct lamparray *la = container_of(ldev, struct lamparray, ldev);
442 u8 r, g, b;
443 int ret;
444
445 if (!la)
446 return -ENODEV;
447 ldev = &la->ldev;
448
> 449 ret = led_mc_calc_color_components(mc, brightness);
450 if (ret)
451 return ret;
452
453 r = mc->subled_info[0].brightness;
454 g = mc->subled_info[1].brightness;
455 b = mc->subled_info[2].brightness;
456
457 ret = lamparray_hw_set_state(ldev, r, g, b, brightness);
458 if (ret)
459 hid_err(ldev->hdev, "Failed to send LampArray update: %d\n",
460 ret);
461
462 mutex_lock(&ldev->lock);
463 ldev->last_r = r;
464 ldev->last_g = g;
465 ldev->last_b = b;
466 ldev->last_brightness = brightness;
467 mutex_unlock(&ldev->lock);
468
469 return 0;
470 }
471
472 static enum led_brightness
473 lamparray_led_brightness_get(struct led_classdev *cdev)
474 {
475 struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
476 struct lamparray_device *ldev =
477 container_of(mc, struct lamparray_device, mc_cdev);
478 enum led_brightness brightness;
479 struct lamparray *la = container_of(ldev, struct lamparray, ldev);
480 u8 rr, gg, bb;
481 enum led_brightness br;
482 int ret;
483
484 /* Default: cache (also used while registering LED classdev) */
485 mutex_lock(&ldev->lock);
486 brightness = ldev->last_brightness;
487 mutex_unlock(&ldev->lock);
488
489 /* Only do HID readback after registration completed */
490 if (READ_ONCE(ldev->led_registered)) {
491 if (!la)
492 return brightness;
493 ldev = &la->ldev;
494
495 ret = lamparray_hw_get_state(ldev, &rr, &gg, &bb, &br);
496 if (ret) {
497 hid_warn(ldev->hdev,
498 "Failed to read LampArray state (%d), using cached brightness %u\n",
499 ret, brightness);
500 return brightness;
501 }
502
503 mutex_lock(&ldev->lock);
504 if (ldev->last_r != rr || ldev->last_g != gg ||
505 ldev->last_b != bb || ldev->last_brightness != br) {
506 ldev->last_r = rr;
507 ldev->last_g = gg;
508 ldev->last_b = bb;
509 ldev->last_brightness = br;
510
511 if (ldev->led_registered && ldev->mc_cdev.subled_info) {
512 ldev->mc_cdev.subled_info[0].brightness = rr;
513 ldev->mc_cdev.subled_info[1].brightness = gg;
514 ldev->mc_cdev.subled_info[2].brightness = bb;
515 }
516 }
517 mutex_unlock(&ldev->lock);
518 return br;
519 }
520 return brightness;
521 }
522
523 static int lamparray_register_led(struct lamparray_device *ldev)
524 {
525 struct device *dev = &ldev->hdev->dev;
526 struct led_classdev *cdev = &ldev->mc_cdev.led_cdev;
527 u8 r_i, g_i, b_i;
528 int ret;
529
530 mutex_lock(&ldev->lock);
531
532 if (ldev->led_registered) {
533 mutex_unlock(&ldev->lock);
534 return 0;
535 }
536
537 if (!cdev->name) {
538 cdev->name =
539 devm_kasprintf(dev, GFP_KERNEL, "%s", dev_name(dev));
540 if (!cdev->name) {
541 mutex_unlock(&ldev->lock);
542 return -ENOMEM;
543 }
544 }
545
546 cdev->max_brightness = 255;
547 cdev->brightness_set_blocking = lamparray_led_brightness_set;
548 cdev->brightness_get = lamparray_led_brightness_get;
549 cdev->brightness = ldev->last_brightness;
550
551 ldev->subleds[0].color_index = LED_COLOR_ID_RED;
552 ldev->subleds[1].color_index = LED_COLOR_ID_GREEN;
553 ldev->subleds[2].color_index = LED_COLOR_ID_BLUE;
554
555 /*
556 * Initialize the color mix (multi_intensity) from the last known HW/init
557 * state so that writing only /brightness scales the expected default color
558 * instead of white.
559 *
560 * If last_brightness is non-zero, treat last_r/g/b as per-channel
561 * brightness and normalize back to intensities (0..255).
562 * If last_brightness is zero, keep last_r/g/b as the intended mix.
563 */
564 if (ldev->last_brightness) {
565 r_i = (u8)min_t(unsigned int, 255,
566 (ldev->last_r * 255u) / ldev->last_brightness);
567 g_i = (u8)min_t(unsigned int, 255,
568 (ldev->last_g * 255u) / ldev->last_brightness);
569 b_i = (u8)min_t(unsigned int, 255,
570 (ldev->last_b * 255u) / ldev->last_brightness);
571 } else {
572 r_i = ldev->last_r;
573 g_i = ldev->last_g;
574 b_i = ldev->last_b;
575 }
576
577 ldev->subleds[0].intensity = r_i;
578 ldev->subleds[1].intensity = g_i;
579 ldev->subleds[2].intensity = b_i;
580
581 ldev->mc_cdev.subled_info = ldev->subleds;
582 ldev->mc_cdev.num_colors = ARRAY_SIZE(ldev->subleds);
583
584 /* Ensure subled_info[].brightness matches intensity + brightness */
585 led_mc_calc_color_components(&ldev->mc_cdev, cdev->brightness);
586
587 ldev->mc_cdev.subled_info = ldev->subleds;
588 ldev->mc_cdev.num_colors = ARRAY_SIZE(ldev->subleds);
589
590 mutex_unlock(&ldev->lock);
591
592 ret = led_classdev_multicolor_register(dev, &ldev->mc_cdev);
593 if (ret)
594 return ret;
595
596 mutex_lock(&ldev->lock);
597 ldev->led_registered = true;
598 mutex_unlock(&ldev->lock);
599
600 return 0;
601 }
602
603 static void lamparray_unregister_led(struct lamparray_device *ldev)
604 {
605 bool was_registered;
606
607 mutex_lock(&ldev->lock);
608 was_registered = ldev->led_registered;
609 ldev->led_registered = false;
610 mutex_unlock(&ldev->lock);
611
612 if (!was_registered)
613 return;
614
> 615 led_classdev_multicolor_unregister(&ldev->mc_cdev);
616 }
617
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