Hi Ludovic, kernel test robot noticed the following build warnings:
[auto build test WARNING on 88cbd8ac379cf5ce68b7efcfd4d1484a6871ee0b] url: https://github.com/intel-lab-lkp/linux/commits/Ludovic-Desroches/drm-panel-simple-restore-connector_type-fallback/20251121-212613 base: 88cbd8ac379cf5ce68b7efcfd4d1484a6871ee0b patch link: https://lore.kernel.org/r/20251121-lcd_panel_connector_type_fix-v1-1-fdbbef34a1a4%40microchip.com patch subject: [PATCH REGRESSION] drm/panel: simple: restore connector_type fallback config: arm-randconfig-002-20251123 (https://download.01.org/0day-ci/archive/20251123/[email protected]/config) compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 9e9fe08b16ea2c4d9867fb4974edf2a3776d6ece) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251123/[email protected]/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 <[email protected]> | Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/ All warnings (new ones prefixed by >>): >> drivers/gpu/drm/panel/panel-simple.c:648:7: warning: variable 'panel' is >> used uninitialized whenever switch case is taken [-Wsometimes-uninitialized] 648 | case DRM_MODE_CONNECTOR_eDP: | ^~~~~~~~~~~~~~~~~~~~~~ include/uapi/drm/drm_mode.h:417:33: note: expanded from macro 'DRM_MODE_CONNECTOR_eDP' 417 | #define DRM_MODE_CONNECTOR_eDP 14 | ^~ drivers/gpu/drm/panel/panel-simple.c:749:6: note: uninitialized use occurs here 749 | if (panel->ddc) | ^~~~~ drivers/gpu/drm/panel/panel-simple.c:615:28: note: initialize the variable 'panel' to silence this warning 615 | struct panel_simple *panel; | ^ | = NULL 1 warning generated. vim +/panel +648 drivers/gpu/drm/panel/panel-simple.c 47c08262f34e1c Maxime Ripard 2025-06-26 611 47c08262f34e1c Maxime Ripard 2025-06-26 612 static struct panel_simple *panel_simple_probe(struct device *dev) 280921de7241ee Thierry Reding 2013-08-30 613 { 47c08262f34e1c Maxime Ripard 2025-06-26 614 const struct panel_desc *desc; 280921de7241ee Thierry Reding 2013-08-30 615 struct panel_simple *panel; b8a2948fa2b3a5 Sean Paul 2019-07-11 616 struct display_timing dt; 0fe1564bd61642 Sam Ravnborg 2019-12-07 617 struct device_node *ddc; 9f069c6fbc7266 Sam Ravnborg 2020-07-26 618 int connector_type; ddb8e853dc8507 Sam Ravnborg 2020-07-26 619 u32 bus_flags; 280921de7241ee Thierry Reding 2013-08-30 620 int err; 280921de7241ee Thierry Reding 2013-08-30 621 47c08262f34e1c Maxime Ripard 2025-06-26 622 desc = panel_simple_get_desc(dev); 47c08262f34e1c Maxime Ripard 2025-06-26 623 if (IS_ERR(desc)) 47c08262f34e1c Maxime Ripard 2025-06-26 624 return ERR_CAST(desc); 47c08262f34e1c Maxime Ripard 2025-06-26 625 9f069c6fbc7266 Sam Ravnborg 2020-07-26 626 connector_type = desc->connector_type; ddb8e853dc8507 Sam Ravnborg 2020-07-26 627 /* Catch common mistakes for panels. */ 9f069c6fbc7266 Sam Ravnborg 2020-07-26 628 switch (connector_type) { ddb8e853dc8507 Sam Ravnborg 2020-07-26 629 case 0: ddb8e853dc8507 Sam Ravnborg 2020-07-26 630 dev_warn(dev, "Specify missing connector_type\n"); 9f069c6fbc7266 Sam Ravnborg 2020-07-26 631 connector_type = DRM_MODE_CONNECTOR_DPI; ddb8e853dc8507 Sam Ravnborg 2020-07-26 632 break; ddb8e853dc8507 Sam Ravnborg 2020-07-26 633 case DRM_MODE_CONNECTOR_LVDS: c4715837b02393 Laurent Pinchart 2020-06-30 634 WARN_ON(desc->bus_flags & c4715837b02393 Laurent Pinchart 2020-06-30 635 ~(DRM_BUS_FLAG_DE_LOW | c4715837b02393 Laurent Pinchart 2020-06-30 636 DRM_BUS_FLAG_DE_HIGH | c4715837b02393 Laurent Pinchart 2020-06-30 637 DRM_BUS_FLAG_DATA_MSB_TO_LSB | c4715837b02393 Laurent Pinchart 2020-06-30 638 DRM_BUS_FLAG_DATA_LSB_TO_MSB)); 1185c406f11a49 Laurent Pinchart 2020-06-30 639 WARN_ON(desc->bus_format != MEDIA_BUS_FMT_RGB666_1X7X3_SPWG && 1185c406f11a49 Laurent Pinchart 2020-06-30 640 desc->bus_format != MEDIA_BUS_FMT_RGB888_1X7X4_SPWG && 1185c406f11a49 Laurent Pinchart 2020-06-30 641 desc->bus_format != MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA); 1185c406f11a49 Laurent Pinchart 2020-06-30 642 WARN_ON(desc->bus_format == MEDIA_BUS_FMT_RGB666_1X7X3_SPWG && 1185c406f11a49 Laurent Pinchart 2020-06-30 643 desc->bpc != 6); 1185c406f11a49 Laurent Pinchart 2020-06-30 644 WARN_ON((desc->bus_format == MEDIA_BUS_FMT_RGB888_1X7X4_SPWG || 1185c406f11a49 Laurent Pinchart 2020-06-30 645 desc->bus_format == MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA) && 1185c406f11a49 Laurent Pinchart 2020-06-30 646 desc->bpc != 8); ddb8e853dc8507 Sam Ravnborg 2020-07-26 647 break; ddb8e853dc8507 Sam Ravnborg 2020-07-26 @648 case DRM_MODE_CONNECTOR_eDP: 5f04e7ce392db9 Douglas Anderson 2021-09-14 649 dev_warn(dev, "eDP panels moved to panel-edp\n"); 5f04e7ce392db9 Douglas Anderson 2021-09-14 650 err = -EINVAL; 5f04e7ce392db9 Douglas Anderson 2021-09-14 651 goto free_ddc; ddb8e853dc8507 Sam Ravnborg 2020-07-26 652 case DRM_MODE_CONNECTOR_DSI: ddb8e853dc8507 Sam Ravnborg 2020-07-26 653 if (desc->bpc != 6 && desc->bpc != 8) ddb8e853dc8507 Sam Ravnborg 2020-07-26 654 dev_warn(dev, "Expected bpc in {6,8} but got: %u\n", desc->bpc); ddb8e853dc8507 Sam Ravnborg 2020-07-26 655 break; ddb8e853dc8507 Sam Ravnborg 2020-07-26 656 case DRM_MODE_CONNECTOR_DPI: ddb8e853dc8507 Sam Ravnborg 2020-07-26 657 bus_flags = DRM_BUS_FLAG_DE_LOW | ddb8e853dc8507 Sam Ravnborg 2020-07-26 658 DRM_BUS_FLAG_DE_HIGH | ddb8e853dc8507 Sam Ravnborg 2020-07-26 659 DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE | ddb8e853dc8507 Sam Ravnborg 2020-07-26 660 DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE | ddb8e853dc8507 Sam Ravnborg 2020-07-26 661 DRM_BUS_FLAG_DATA_MSB_TO_LSB | ddb8e853dc8507 Sam Ravnborg 2020-07-26 662 DRM_BUS_FLAG_DATA_LSB_TO_MSB | ddb8e853dc8507 Sam Ravnborg 2020-07-26 663 DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE | ddb8e853dc8507 Sam Ravnborg 2020-07-26 664 DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE; ddb8e853dc8507 Sam Ravnborg 2020-07-26 665 if (desc->bus_flags & ~bus_flags) ddb8e853dc8507 Sam Ravnborg 2020-07-26 666 dev_warn(dev, "Unexpected bus_flags(%d)\n", desc->bus_flags & ~bus_flags); ddb8e853dc8507 Sam Ravnborg 2020-07-26 667 if (!(desc->bus_flags & bus_flags)) ddb8e853dc8507 Sam Ravnborg 2020-07-26 668 dev_warn(dev, "Specify missing bus_flags\n"); ddb8e853dc8507 Sam Ravnborg 2020-07-26 669 if (desc->bus_format == 0) ddb8e853dc8507 Sam Ravnborg 2020-07-26 670 dev_warn(dev, "Specify missing bus_format\n"); ddb8e853dc8507 Sam Ravnborg 2020-07-26 671 if (desc->bpc != 6 && desc->bpc != 8) ddb8e853dc8507 Sam Ravnborg 2020-07-26 672 dev_warn(dev, "Expected bpc in {6,8} but got: %u\n", desc->bpc); ddb8e853dc8507 Sam Ravnborg 2020-07-26 673 break; ddb8e853dc8507 Sam Ravnborg 2020-07-26 674 default: ddb8e853dc8507 Sam Ravnborg 2020-07-26 675 dev_warn(dev, "Specify a valid connector_type: %d\n", desc->connector_type); 9f069c6fbc7266 Sam Ravnborg 2020-07-26 676 connector_type = DRM_MODE_CONNECTOR_DPI; ddb8e853dc8507 Sam Ravnborg 2020-07-26 677 break; 1185c406f11a49 Laurent Pinchart 2020-06-30 678 } c4715837b02393 Laurent Pinchart 2020-06-30 679 2803eb4aeb2702 Ludovic Desroches 2025-11-21 680 panel = devm_drm_panel_alloc(dev, struct panel_simple, base, 2803eb4aeb2702 Ludovic Desroches 2025-11-21 681 &panel_simple_funcs, connector_type); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 682 if (IS_ERR(panel)) 2803eb4aeb2702 Ludovic Desroches 2025-11-21 683 return ERR_CAST(panel); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 684 2803eb4aeb2702 Ludovic Desroches 2025-11-21 685 panel->desc = desc; 2803eb4aeb2702 Ludovic Desroches 2025-11-21 686 2803eb4aeb2702 Ludovic Desroches 2025-11-21 687 panel->supply = devm_regulator_get(dev, "power"); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 688 if (IS_ERR(panel->supply)) 2803eb4aeb2702 Ludovic Desroches 2025-11-21 689 return ERR_CAST(panel->supply); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 690 2803eb4aeb2702 Ludovic Desroches 2025-11-21 691 panel->enable_gpio = devm_gpiod_get_optional(dev, "enable", 2803eb4aeb2702 Ludovic Desroches 2025-11-21 692 GPIOD_OUT_LOW); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 693 if (IS_ERR(panel->enable_gpio)) 2803eb4aeb2702 Ludovic Desroches 2025-11-21 694 return dev_err_cast_probe(dev, panel->enable_gpio, 2803eb4aeb2702 Ludovic Desroches 2025-11-21 695 "failed to request GPIO\n"); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 696 2803eb4aeb2702 Ludovic Desroches 2025-11-21 697 err = of_drm_get_panel_orientation(dev->of_node, &panel->orientation); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 698 if (err) { 2803eb4aeb2702 Ludovic Desroches 2025-11-21 699 dev_err(dev, "%pOF: failed to get orientation %d\n", dev->of_node, err); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 700 return ERR_PTR(err); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 701 } 2803eb4aeb2702 Ludovic Desroches 2025-11-21 702 2803eb4aeb2702 Ludovic Desroches 2025-11-21 703 ddc = of_parse_phandle(dev->of_node, "ddc-i2c-bus", 0); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 704 if (ddc) { 2803eb4aeb2702 Ludovic Desroches 2025-11-21 705 panel->ddc = of_find_i2c_adapter_by_node(ddc); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 706 of_node_put(ddc); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 707 2803eb4aeb2702 Ludovic Desroches 2025-11-21 708 if (!panel->ddc) 2803eb4aeb2702 Ludovic Desroches 2025-11-21 709 return ERR_PTR(-EPROBE_DEFER); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 710 } 2803eb4aeb2702 Ludovic Desroches 2025-11-21 711 2803eb4aeb2702 Ludovic Desroches 2025-11-21 712 if (!of_device_is_compatible(dev->of_node, "panel-dpi") && 2803eb4aeb2702 Ludovic Desroches 2025-11-21 713 !of_get_display_timing(dev->of_node, "panel-timing", &dt)) 2803eb4aeb2702 Ludovic Desroches 2025-11-21 714 panel_simple_parse_panel_timing_node(dev, panel, &dt); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 715 2803eb4aeb2702 Ludovic Desroches 2025-11-21 716 if (desc->connector_type == DRM_MODE_CONNECTOR_LVDS) { 2803eb4aeb2702 Ludovic Desroches 2025-11-21 717 /* Optional data-mapping property for overriding bus format */ 2803eb4aeb2702 Ludovic Desroches 2025-11-21 718 err = panel_simple_override_nondefault_lvds_datamapping(dev, panel); 2803eb4aeb2702 Ludovic Desroches 2025-11-21 719 if (err) 2803eb4aeb2702 Ludovic Desroches 2025-11-21 720 goto free_ddc; 2803eb4aeb2702 Ludovic Desroches 2025-11-21 721 } 2803eb4aeb2702 Ludovic Desroches 2025-11-21 722 3235b0f20a0a41 Douglas Anderson 2021-04-16 723 dev_set_drvdata(dev, panel); 3235b0f20a0a41 Douglas Anderson 2021-04-16 724 3235b0f20a0a41 Douglas Anderson 2021-04-16 725 /* 3235b0f20a0a41 Douglas Anderson 2021-04-16 726 * We use runtime PM for prepare / unprepare since those power the panel 3235b0f20a0a41 Douglas Anderson 2021-04-16 727 * on and off and those can be very slow operations. This is important 3235b0f20a0a41 Douglas Anderson 2021-04-16 728 * to optimize powering the panel on briefly to read the EDID before 3235b0f20a0a41 Douglas Anderson 2021-04-16 729 * fully enabling the panel. 3235b0f20a0a41 Douglas Anderson 2021-04-16 730 */ 3235b0f20a0a41 Douglas Anderson 2021-04-16 731 pm_runtime_enable(dev); 3235b0f20a0a41 Douglas Anderson 2021-04-16 732 pm_runtime_set_autosuspend_delay(dev, 1000); 3235b0f20a0a41 Douglas Anderson 2021-04-16 733 pm_runtime_use_autosuspend(dev); 3235b0f20a0a41 Douglas Anderson 2021-04-16 734 0fe1564bd61642 Sam Ravnborg 2019-12-07 735 err = drm_panel_of_backlight(&panel->base); d9e74da2f1fc42 Alexander Stein 2022-06-21 736 if (err) { d9e74da2f1fc42 Alexander Stein 2022-06-21 737 dev_err_probe(dev, err, "Could not find backlight\n"); 70e12560126685 Douglas Anderson 2021-04-23 738 goto disable_pm_runtime; d9e74da2f1fc42 Alexander Stein 2022-06-21 739 } 0fe1564bd61642 Sam Ravnborg 2019-12-07 740 c3ee8c65f63799 Bernard Zhao 2020-08-01 741 drm_panel_add(&panel->base); 280921de7241ee Thierry Reding 2013-08-30 742 921c41e509746a Maxime Ripard 2025-06-26 743 return panel; 280921de7241ee Thierry Reding 2013-08-30 744 70e12560126685 Douglas Anderson 2021-04-23 745 disable_pm_runtime: a596fcd9cbc781 Douglas Anderson 2021-05-17 746 pm_runtime_dont_use_autosuspend(dev); 70e12560126685 Douglas Anderson 2021-04-23 747 pm_runtime_disable(dev); 280921de7241ee Thierry Reding 2013-08-30 748 free_ddc: 5f04e7ce392db9 Douglas Anderson 2021-09-14 749 if (panel->ddc) 280921de7241ee Thierry Reding 2013-08-30 750 put_device(&panel->ddc->dev); 280921de7241ee Thierry Reding 2013-08-30 751 921c41e509746a Maxime Ripard 2025-06-26 752 return ERR_PTR(err); 280921de7241ee Thierry Reding 2013-08-30 753 } 280921de7241ee Thierry Reding 2013-08-30 754 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
