Public bug reported:
Brightness control is not working on my ASUS TUF Gaming A15 FA506NCG
running Ubuntu 26.04.
Hardware:
* ASUS TUF Gaming A15 FA506NCG
* AMD HawkPoint integrated GPU
* NVIDIA RTX 3050 Mobile
* BIOS Version: FA506NCG.301
* BIOS Date: 2025-06-18
Kernel:
* 7.0.0-1005-oem
Issue:
The GNOME brightness slider appears and changes value, but the physical laptop
screen brightness never changes.
Observed behavior:
* Brightness slider is visible.
* Brightness hotkeys are detected by the system.
* brightnessctl successfully changes values under nvidia_wmi_ec_backlight.
* The value changes from 20 to 180 and vice versa.
* Actual display brightness remains unchanged.
Diagnostics:
* Internal display is detected as eDP-1.
* Display panel model: N156HRA-EA1.
* /sys/class/backlight contains only nvidia_wmi_ec_backlight.
* dmesg shows:
amdgpu 0000:05:00.0: [drm] Skipping amdgpu DM backlight registration
Expected behavior:
Changing brightness through GNOME or keyboard hotkeys should adjust the
physical panel brightness.
The screen flickering does not occur during normal use of the laptop's
internal display alone.
The flickering is observed when an external display is connected.
Observed behavior:
Internal panel: N156HRA-EA1
External monitor connected through HDMI
Occasional display flickering occurs while using an external display
Brightness control issue remains present even when no external display is
connected
Flickering and brightness-control problems may be related to the AMD display
driver stack
Relevant kernel message:
amdgpu 0000:05:00.0: [drm] Skipping amdgpu DM backlight registration
Please note that the brightness-control issue and the external-display
flickering issue may be separate problems, although both appear to
involve the display subsystem.
** Affects: linux-signed-oem-7.0 (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute wayland-session
** Description changed:
Brightness control is not working on my ASUS TUF Gaming A15 FA506NCG
running Ubuntu 26.04.
Hardware:
* ASUS TUF Gaming A15 FA506NCG
* AMD HawkPoint integrated GPU
* NVIDIA RTX 3050 Mobile
* BIOS Version: FA506NCG.301
* BIOS Date: 2025-06-18
Kernel:
* 7.0.0-1005-oem
Issue:
The GNOME brightness slider appears and changes value, but the physical
laptop screen brightness never changes.
Observed behavior:
* Brightness slider is visible.
* Brightness hotkeys are detected by the system.
* brightnessctl successfully changes values under nvidia_wmi_ec_backlight.
* The value changes from 20 to 180 and vice versa.
* Actual display brightness remains unchanged.
Diagnostics:
* Internal display is detected as eDP-1.
* Display panel model: N156HRA-EA1.
* /sys/class/backlight contains only nvidia_wmi_ec_backlight.
* dmesg shows:
- amdgpu 0000:05:00.0: [drm] Skipping amdgpu DM backlight registration
+ amdgpu 0000:05:00.0: [drm] Skipping amdgpu DM backlight registration
Expected behavior:
Changing brightness through GNOME or keyboard hotkeys should adjust the
physical panel brightness.
+ The screen flickering does not occur during normal use of the laptop's
+ internal display alone.
- Additional Issue:
-
- I am also experiencing occasional screen flickering on the internal
- laptop display.
+ The flickering is observed when an external display is connected.
Observed behavior:
- * Brief brightness fluctuations and display flickering.
- * Occurs on the built-in eDP panel.
- * External displays have not been tested extensively.
- * Flickering appears independent of the GNOME brightness slider.
- * The issue started on Ubuntu 26.04.
+ Internal panel: N156HRA-EA1
+ External monitor connected through HDMI
+ Occasional display flickering occurs while using an external display
+ Brightness control issue remains present even when no external display is
connected
+ Flickering and brightness-control problems may be related to the AMD display
driver stack
- This may be related to the AMD display driver because the system
- reports:
+ Relevant kernel message:
amdgpu 0000:05:00.0: [drm] Skipping amdgpu DM backlight registration
- The internal display panel is detected as:
- N156HRA-EA1
-
- ProblemType: Bug
- DistroRelease: Ubuntu 26.04
- Package: linux-image-7.0.0-1005-oem 7.0.0-1005.5
- ProcVersionSignature: Ubuntu 7.0.0-1005.5-oem 7.0.2
- Uname: Linux 7.0.0-1005-oem x86_64
- ApportVersion: 2.34.0-0ubuntu2
- Architecture: amd64
- CasperMD5CheckResult: pass
- CurrentDesktop: ubuntu:GNOME
- Date: Sun May 31 01:36:56 2026
- InstallationDate: Installed on 2026-05-14 (16 days ago)
- InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64
(20260423.1)
- SourcePackage: linux-signed-oem-7.0
- UpgradeStatus: No upgrade log present (probably fresh install)
+ Please note that the brightness-control issue and the external-display
+ flickering issue may be separate problems, although both appear to
+ involve the display subsystem.
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https://bugs.launchpad.net/bugs/2154649
Title:
ASUS TUF Gaming A15 FA506NCG brightness control does not affect
display brightness ans screen flicker issue
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