Hi,
On 11/22/25 21:26, kernel test robot wrote:
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;
The error is legitimate, here we'll try to access panel->ddc, but the panel
isn't allocated.
Please fix this.
Neil
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
