Screen has max brightness after wake up

blindfish · 2025-11-06 19:00:22

I love XUBUNTU since more than 10 years. Now I got a new Lenovo Yoga 7 2-in-1 16ILL10 with OLED screen that's giving me headaches. It took me some time to find out that I had to upgrade the kernel to 6.14 in order to get access to the brightness control. The function keys (F5 and F6) work now, I can use brightnessctl and the slider of the power managment icon works too. BUT:
The device boots with the last brightness level until I entered the password in the login screen. Then the screen switches to max brightness. Pushing one of the function keys sets the brightness to plus (F5) or minus (F6) one of the last brightness level. So the last brightness level is stored somewhere (/sys/class/backlight/intel_backlight/brightness contains the right value) but this level seems to be ignored then.
The screen also starts with max brightness when the power manager had switched off the screen, I used 'xset dpms force off' or the screensaver had turned the screen off.
Here is some information about my system:
xfce4-about

$ uname -a
Linux elke-Yoga 6.14.0-35-generic #35~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Tue Oct 14 13:55:17 UTC 2 x86_64 x86_64 x86_64 GNU/Linux

$ inxi -SMGxxxz --vs
inxi 3.3.34-00 (2024-04-13)
System:
  Kernel: 6.14.0-35-generic arch: x86_64 bits: 64 compiler: gcc v: 13.3.0
    clocksource: tsc
  Desktop: Xfce v: 4.18.1 tk: Gtk v: 3.24.41 wm: xfwm4 v: 4.18.0
    with: xfce4-panel tools: xfce4-screensaver vt: 7 dm: LightDM v: 1.30.0
    Distro: Xubuntu 24.04.3 LTS (Noble Numbat) base: Ubuntu
Machine:
  Type: Convertible System: LENOVO product: 83JT v: Yoga 7 2-in-1 16ILL10
    serial: <superuser required> Chassis: type: 31 v: Yoga 7 2-in-1 16ILL10
    serial: <superuser required>
  Mobo: LENOVO model: LNVNB161216 v: SDK0T76574 WIN
    serial: <superuser required> part-nu: LENOVO_MT_83JT_BU_idea_FM_Yoga 7
    2-in-1 16ILL10 uuid: <superuser required> UEFI: LENOVO v: QPCN13WW
    date: 02/19/2025
Graphics:
  Device-1: Intel Lunar Lake [Intel Graphics] vendor: Lenovo driver: xe
    v: kernel arch: Gen-14 ports: active: DP-3,eDP-1 empty: DP-1, DP-2, DP-4,
    DP-5, HDMI-A-1 bus-ID: 00:02.0 chip-ID: 8086:64a0 class-ID: 0300
  Device-2: Chicony Integrated Camera driver: hid-sensor-hub,usbhid,uvcvideo
    type: USB rev: 2.0 speed: 480 Mb/s lanes: 1 bus-ID: 3-5:4 chip-ID: 04f2:b83c
    class-ID: fe01 serial: <filter>
  Display: x11 server: X.Org v: 21.1.11 compositor: xfwm4 v: 4.18.0 driver:
    X: loaded: modesetting unloaded: fbdev,vesa dri: iris gpu: xe
    display-ID: :0.0 screens: 1
  Screen-1: 0 s-res: 2560x1440 s-dpi: 96 s-size: 677x381mm (26.65x15.00")
    s-diag: 777mm (30.58")
  Monitor-1: DP-3 mapped: DP-1-1 pos: primary model: Lenovo R27qe
    serial: <filter> res: 2560x1440 hz: 60 dpi: 109
    size: 597x336mm (23.5x13.23") diag: 685mm (27") modes: max: 2560x1440
    min: 720x400
  Monitor-2: eDP-1 pos: primary model: Samsung ATNA60HR01-0 res: 2560x1440
    hz: 60 dpi: 191 size: 340x220mm (13.39x8.66") diag: 405mm (15.9")
    modes: 2880x1800
  API: EGL v: 1.5 hw: drv: intel iris platforms: device: 0 drv: iris
    device: 1 drv: swrast gbm: drv: iris surfaceless: drv: iris x11: drv: iris
    inactive: wayland
  API: OpenGL v: 4.6 compat-v: 4.5 vendor: intel mesa
    v: 25.0.7-0ubuntu0.24.04.2 glx-v: 1.4 direct-render: yes renderer: Mesa
    Intel Graphics (LNL) device-ID: 8086:64a0

$ xfconf-query -c xfce4-power-manager -lv
/xfce4-power-manager/blank-on-ac                        1
/xfce4-power-manager/blank-on-battery                   2
/xfce4-power-manager/brightness-exponential             false
/xfce4-power-manager/brightness-level-on-ac             10
/xfce4-power-manager/brightness-level-on-battery        20
/xfce4-power-manager/brightness-on-ac                   9
/xfce4-power-manager/brightness-on-battery              120
/xfce4-power-manager/brightness-switch                  0
/xfce4-power-manager/brightness-switch-restore-on-exit  1
/xfce4-power-manager/critical-power-action              1
/xfce4-power-manager/critical-power-level               15
/xfce4-power-manager/dpms-enabled                       true
/xfce4-power-manager/dpms-on-ac-off                     0
/xfce4-power-manager/dpms-on-ac-sleep                   0
/xfce4-power-manager/dpms-on-battery-off                30
/xfce4-power-manager/dpms-on-battery-sleep              15
/xfce4-power-manager/handle-brightness-keys             true
/xfce4-power-manager/inactivity-on-ac                   60
/xfce4-power-manager/inactivity-on-battery              60
/xfce4-power-manager/inactivity-sleep-mode-on-ac        1
/xfce4-power-manager/inactivity-sleep-mode-on-battery   1
/xfce4-power-manager/lid-action-on-ac                   1
/xfce4-power-manager/lid-action-on-battery              1
/xfce4-power-manager/lock-screen-suspend-hibernate      false
/xfce4-power-manager/logind-handle-lid-switch           false
/xfce4-power-manager/power-button-action                3
/xfce4-power-manager/show-panel-label                   0
/xfce4-power-manager/show-tray-icon                     false

$lspci
00:00.0 Host bridge: Intel Corporation Device 6400 (rev 04)
00:02.0 VGA compatible controller: Intel Corporation Lunar Lake [Intel Graphics] (rev 04)
00:04.0 Signal processing controller: Intel Corporation Device 641d (rev 04)
00:07.0 PCI bridge: Intel Corporation Lunar Lake-M Thunderbolt 4 PCI Express Root Port #0 (rev 10)
00:07.2 PCI bridge: Intel Corporation Lunar Lake-M Thunderbolt 4 PCI Express Root Port #2 (rev 10)
00:0a.0 Signal processing controller: Intel Corporation Device 647d (rev 04)
00:0b.0 Processing accelerators: Intel Corporation Lunar Lake NPU (rev 04)
00:0d.0 USB controller: Intel Corporation Lunar Lake-M Thunderbolt 4 USB Controller (rev 10)
00:0d.2 USB controller: Intel Corporation Lunar Lake-M Thunderbolt 4 NHI #0 (rev 10)
00:0d.3 USB controller: Intel Corporation Lunar Lake-M Thunderbolt 4 NHI #1 (rev 10)
00:12.0 Serial controller: Intel Corporation Lunar Lake-M Integrated Sensor Hub (rev 10)
00:13.0 Communication controller: Intel Corporation Device a862 (rev 10)
00:14.0 USB controller: Intel Corporation Lunar Lake-M USB 3.2 Gen 2x1 xHCI Host Controller (rev 10)
00:14.2 RAM memory: Intel Corporation Device a87f (rev 10)
00:15.0 Serial bus controller: Intel Corporation Lunar Lake-M Serial IO I2C Controller #0 (rev 10)
00:16.0 Communication controller: Intel Corporation Device a870 (rev 10)
00:19.0 Serial bus controller: Intel Corporation Device a850 (rev 10)
00:19.1 Serial bus controller: Intel Corporation Device a851 (rev 10)
00:1c.0 PCI bridge: Intel Corporation Lunar Lake-M PCI Express Root Port #1 (rev 10)
00:1c.2 PCI bridge: Intel Corporation Lunar Lake-M PCI Express Root Port #3 (rev 10)
00:1c.4 PCI bridge: Intel Corporation Lunar Lake-M PCI Express Root Port #5 (rev 10)
00:1f.0 ISA bridge: Intel Corporation Device a807 (rev 10)
00:1f.3 Multimedia audio controller: Intel Corporation Lunar Lake-M HD Audio Controller (rev 10)
00:1f.4 SMBus: Intel Corporation Lunar Lake-M SMbus Controller (rev 10)
00:1f.5 Serial bus controller: Intel Corporation Lunar Lake-M SPI Controller (rev 10)
55:00.0 SD Host controller: O2 Micro, Inc. SD/MMC Card Reader Controller (rev 01)
56:00.0 Network controller: MEDIATEK Corp. Device 7925
57:00.0 Non-Volatile memory controller: SK hynix Device 1f69

What I tried so far:

Searched for similar topics in various forums. Most are quite old. Some are related to different graphic chips. None of the solutions does work in my case.
Exchanged xfce4-screensaver with xscreensaver -> same problem.
Tried various combinations of power manager settings -> no luck.
Tried to alter kernel parameters related to screen brightness -> no success.

In the past I got most problems solved by myself (with input from the web, of course) but now I'm stuck and need help from the gurus.

eriefisher · 2025-11-06 21:13:57

I don't know the syntax off hand but you could create a script to set the brightness and have it run at login. Place it in your autostart folder.

blindfish · 2025-11-06 22:12:30

Thanks for your proposal. This workaround would probably work, but I don't like the idea of having to login in each time the screensaver kicked in.There must be a smarter way, because the old status is present in the system and this status should be set instead of switching to the highest brightness....
Nevertheless, your proposal could serve as a preliminary solution if the script you have in mind could be executed not only after login but also whenever the screen changes from off to active. Xscreensaver provides a hook for that: https://forums.freebsd.org/threads/disp … ing.78236/
I'll try to find out if this could be done with XFCE-screensaver, too.

ToZ · 2025-11-07 13:25:42

Thanks for your proposal. This workaround would probably work, but I don't like the idea of having to login in each time the screensaver kicked in.There must be a smarter way, because the old status is present in the system and this status should be set instead of switching to the highest brightness....

Are you saying that the brightness switches everytime you return from the screensaver? Your initial post indicated that this only happened at boot.

Monitor-1: DP-3 mapped: DP-1-1 pos: primary model: Lenovo R27qe
serial: <filter> res: 2560x1440 hz: 60 dpi: 109
size: 597x336mm (23.5x13.23") diag: 685mm (27") modes: max: 2560x1440
min: 720x400
Monitor-2: eDP-1 pos: primary model: Samsung ATNA60HR01-0 res: 2560x1440
hz: 60 dpi: 191 size: 340x220mm (13.39x8.66") diag: 405mm (15.9")
modes: 2880x1800

Also, you seem to have an external monitor plugged in. Does the brightness issue occur on just one of the screens or both? What happens if you boot with the external monitor disconnected?

Does your laptop have an "adaptive brightness" feature, and if so, are you able to disable it at the bios level?

blindfish · 2025-11-07 19:46:41

Thank you for having a look at my problem. Yes, every time the screen (OLED screen of the Notebook) switches on after it had gone black due to the screensaver, it switches to full brightness. The same happens after boot login (the login screen itself has still the right brightness) and after wakeup from supend.
Yes, I have a second monitor connected. The brightness of this monitor doesn't change at all. It is simply switched on or off. For the notebook it doesn't matter if the external monitor is connected or not. The issue remains the same with or without it. As far as I can see, the laptop doesn't have an "adaptive brightness". At least, I can't see any switch for such an option and I never used it with Windows. Installing XUBUNTU was my first action when I received the device.

eriefisher · 2025-11-07 19:58:52

I didn't catch that this was an OLED screen. This may complicate things.
https://wiki.archlinux.org/title/Backlight

Since OLED screens have no backlight, brightness cannot be controlled by changing backlight power on laptops equipped with an OLED screen. In this case, perceived screen brightness can be adjusted with a PWM control (not implemented in the Linux kernel) or via software color correction.

There is more in the wiki link and a link to a oled script on github.

blindfish · 2025-11-07 20:22:49

Thank you for the link. I know this content and I also tried the grub option "acpi_backlight=native". I got a second directory named "Ideapad" in /sys/class/backlight then and I couldn't change the brightness anymore with function keys or brightnessctl. I never tried the udev rule because solving the problem for boot alone is not enough. The links to github lead to tools for altering the brightness. I don't need that because brightnessctl works fine.

I made a mistake answering the questions from ToZ: If I boot the notebook without the second monitor, I get the right brightness. But as soon as the screensaver switched the screen off, I get the max brightness again.

When I started this thread I forgot to mention that I installed the newest driver for the graphics from the Intel homepage.That didn't change anything.

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#1 2025-11-06 19:00:22

Screen has max brightness after wake up

#2 2025-11-06 21:13:57

Re: Screen has max brightness after wake up

#3 2025-11-06 22:12:30

Re: Screen has max brightness after wake up

#4 2025-11-07 13:25:42

Re: Screen has max brightness after wake up

#5 2025-11-07 19:46:41

Re: Screen has max brightness after wake up

#6 2025-11-07 19:58:52

Re: Screen has max brightness after wake up

#7 2025-11-07 20:22:49

Re: Screen has max brightness after wake up

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