* [PATCH] ACPI: video: Replace backlight_device_register() with devm variant
@ 2025-10-07 3:07 Kaushlendra Kumar
2025-10-10 10:18 ` kernel test robot
0 siblings, 1 reply; 2+ messages in thread
From: Kaushlendra Kumar @ 2025-10-07 3:07 UTC (permalink / raw)
To: rafael, lenb; +Cc: linux-acpi, Kaushlendra Kumar
Replace deprecated backlight_device_register() with
devm_backlight_device_register() to use device-managed
resource allocation. This automatically handles backlight
device cleanup when the device is removed, eliminating the
need for manual backlight_device_unregister() calls.
Remove the manual cleanup code in acpi_video_dev_unregister_backlight()
as the managed version handles deregistration automatically.
Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com>
---
drivers/acpi/acpi_video.c | 19 +++++++------------
1 file changed, 7 insertions(+), 12 deletions(-)
diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c
index 103f29661576..e56665977ed7 100644
--- a/drivers/acpi/acpi_video.c
+++ b/drivers/acpi/acpi_video.c
@@ -1741,16 +1741,15 @@ static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
props.type = BACKLIGHT_FIRMWARE;
props.max_brightness =
device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
- device->backlight = backlight_device_register(name,
- parent,
- device,
- &acpi_backlight_ops,
- &props);
+ device->backlight = devm_backlight_device_register(&pdev->dev,
+ name,
+ parent,
+ device,
+ &acpi_backlight_ops,
+ &props);
kfree(name);
- if (IS_ERR(device->backlight)) {
- device->backlight = NULL;
+ if (IS_ERR(device->backlight))
return;
- }
/*
* Save current brightness level in case we have to restore it
@@ -1841,10 +1840,6 @@ static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
{
- if (device->backlight) {
- backlight_device_unregister(device->backlight);
- device->backlight = NULL;
- }
if (device->brightness) {
kfree(device->brightness->levels);
kfree(device->brightness);
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] ACPI: video: Replace backlight_device_register() with devm variant
2025-10-07 3:07 [PATCH] ACPI: video: Replace backlight_device_register() with devm variant Kaushlendra Kumar
@ 2025-10-10 10:18 ` kernel test robot
0 siblings, 0 replies; 2+ messages in thread
From: kernel test robot @ 2025-10-10 10:18 UTC (permalink / raw)
To: Kaushlendra Kumar, rafael, lenb
Cc: llvm, oe-kbuild-all, linux-acpi, Kaushlendra Kumar
Hi Kaushlendra,
kernel test robot noticed the following build warnings:
[auto build test WARNING on rafael-pm/linux-next]
[also build test WARNING on rafael-pm/bleeding-edge linus/master v6.17 next-20251009]
[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/Kaushlendra-Kumar/ACPI-video-Replace-backlight_device_register-with-devm-variant/20251010-133230
base: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
patch link: https://lore.kernel.org/r/20251007030730.3192901-1-kaushlendra.kumar%40intel.com
patch subject: [PATCH] ACPI: video: Replace backlight_device_register() with devm variant
config: i386-buildonly-randconfig-002-20251010 (https://download.01.org/0day-ci/archive/20251010/202510101817.Xkl2fc9D-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251010/202510101817.Xkl2fc9D-lkp@intel.com/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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202510101817.Xkl2fc9D-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> drivers/acpi/acpi_video.c:1732:6: warning: variable 'pdev' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
1732 | if (ACPI_SUCCESS(acpi_get_parent(device->dev->handle, &acpi_parent))) {
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/acpi/acexcep.h:57:41: note: expanded from macro 'ACPI_SUCCESS'
57 | #define ACPI_SUCCESS(a) (!(a))
| ^~~~~~
drivers/acpi/acpi_video.c:1744:54: note: uninitialized use occurs here
1744 | device->backlight = devm_backlight_device_register(&pdev->dev,
| ^~~~
drivers/acpi/acpi_video.c:1732:2: note: remove the 'if' if its condition is always true
1732 | if (ACPI_SUCCESS(acpi_get_parent(device->dev->handle, &acpi_parent))) {
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/acpi/acpi_video.c:1716:22: note: initialize the variable 'pdev' to silence this warning
1716 | struct pci_dev *pdev;
| ^
| = NULL
1 warning generated.
vim +1732 drivers/acpi/acpi_video.c
c504f8cb68eb0d drivers/acpi/video.c Zhang Rui 2009-12-30 1712
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1713 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1714 {
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1715 struct backlight_properties props;
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1716 struct pci_dev *pdev;
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1717 acpi_handle acpi_parent;
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1718 struct device *parent = NULL;
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1719 int result;
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1720 static int count;
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1721 char *name;
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1722
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1723 result = acpi_video_init_brightness(device);
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1724 if (result)
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1725 return;
654a182d8562d5 drivers/acpi/video.c Hans de Goede 2015-06-09 1726
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1727 name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1728 if (!name)
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1729 return;
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1730 count++;
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1731
ccd45faf497374 drivers/acpi/acpi_video.c Nikita Kiryushin 2023-11-09 @1732 if (ACPI_SUCCESS(acpi_get_parent(device->dev->handle, &acpi_parent))) {
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1733 pdev = acpi_get_pci_dev(acpi_parent);
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1734 if (pdev) {
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1735 parent = &pdev->dev;
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1736 pci_dev_put(pdev);
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1737 }
ccd45faf497374 drivers/acpi/acpi_video.c Nikita Kiryushin 2023-11-09 1738 }
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1739
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1740 memset(&props, 0, sizeof(struct backlight_properties));
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1741 props.type = BACKLIGHT_FIRMWARE;
d485ef43072e54 drivers/acpi/acpi_video.c Dmitry Frank 2017-04-19 1742 props.max_brightness =
d485ef43072e54 drivers/acpi/acpi_video.c Dmitry Frank 2017-04-19 1743 device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
ef5cc540f10200 drivers/acpi/acpi_video.c Kaushlendra Kumar 2025-10-07 1744 device->backlight = devm_backlight_device_register(&pdev->dev,
ef5cc540f10200 drivers/acpi/acpi_video.c Kaushlendra Kumar 2025-10-07 1745 name,
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1746 parent,
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1747 device,
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1748 &acpi_backlight_ops,
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1749 &props);
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1750 kfree(name);
ef5cc540f10200 drivers/acpi/acpi_video.c Kaushlendra Kumar 2025-10-07 1751 if (IS_ERR(device->backlight))
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1752 return;
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1753
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1754 /*
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1755 * Save current brightness level in case we have to restore it
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1756 * before acpi_video_device_lcd_set_level() is called next time.
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1757 */
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1758 device->backlight->props.brightness =
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1759 acpi_video_get_brightness(device->backlight);
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1760
172c48caed91a9 drivers/acpi/acpi_video.c Hans de Goede 2023-11-27 1761 device->cooling_dev = thermal_cooling_device_register("LCD", device,
172c48caed91a9 drivers/acpi/acpi_video.c Hans de Goede 2023-11-27 1762 &video_cooling_ops);
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1763 if (IS_ERR(device->cooling_dev)) {
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1764 /*
99678ed73a50d2 drivers/acpi/video.c Hans de Goede 2014-05-15 1765 * Set cooling_dev to NULL so we don't crash trying to free it.
99678ed73a50d2 drivers/acpi/video.c Hans de Goede 2014-05-15 1766 * Also, why the hell we are returning early and not attempt to
99678ed73a50d2 drivers/acpi/video.c Hans de Goede 2014-05-15 1767 * register video output if cooling device registration failed?
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1768 * -- dtor
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1769 */
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1770 device->cooling_dev = NULL;
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1771 return;
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1772 }
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1773
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1774 dev_info(&device->dev->dev, "registered as cooling_device%d\n",
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1775 device->cooling_dev->id);
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1776 result = sysfs_create_link(&device->dev->dev.kobj,
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1777 &device->cooling_dev->device.kobj,
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1778 "thermal_cooling");
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1779 if (result)
2924d2f837788b drivers/acpi/acpi_video.c Rafael J. Wysocki 2021-02-03 1780 pr_info("sysfs link creation failed\n");
2924d2f837788b drivers/acpi/acpi_video.c Rafael J. Wysocki 2021-02-03 1781
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1782 result = sysfs_create_link(&device->cooling_dev->device.kobj,
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1783 &device->dev->dev.kobj, "device");
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1784 if (result)
2924d2f837788b drivers/acpi/acpi_video.c Rafael J. Wysocki 2021-02-03 1785 pr_info("Reverse sysfs link creation failed\n");
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1786 }
67b662e189f469 drivers/acpi/video.c Aaron Lu 2013-10-11 1787
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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2025-10-10 10:18 ` kernel test robot
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