Can no longer adjust backlight down to absolute 0% [LM21 Cinnamon]

[Reserved_for_future]

Hello, I recently installed Mint 21 Cinnamon (clean installation after Mint Cinnamon 20.1), and no longer can set brightness to 0% - on-screen "notification" says that it is 0%, but in /sys/class/backlight/intel_backlight/brightness it is set to 8 (from maximum 400). In Mint 20 and 20.1 I was able to adjust brightness to absolute zero, which disabled my OLED screen completely. Is there a way to sen minimum backlight level?

inxi if needed:

Code: Select all

mi@Lain:~$ inxi -Fxxxrz
System:
  Kernel: 5.15.0-48-generic x86_64 bits: 64 compiler: gcc v: 11.2.0
    Desktop: Cinnamon 5.4.12 tk: GTK 3.24.33 wm: Mutter vt: 7
    dm: LightDM 1.30.0 Distro: Linux Mint 21 Vanessa base: Ubuntu 22.04 jammy
Machine:
  Type: Convertible System: HP product: HP ENVY x360 Convertible 13-bd0xxx
    v: Type1ProductConfigId serial: <superuser required> Chassis: type: 31
    serial: <superuser required>
  Mobo: HP model: 8824 v: 47.45 serial: <superuser required> UEFI: Insyde
    v: F.31 date: 03/29/2022
CPU:
  Info: quad core model: 11th Gen Intel Core i7-1165G7 bits: 64 type: MT MCP
    smt: enabled arch: Tiger Lake rev: 1 cache: L1: 320 KiB L2: 5 MiB
    L3: 12 MiB
  Speed (MHz): avg: 976 high: 1353 min/max: 400/4700 cores: 1: 1078 2: 865
    3: 1353 4: 866 5: 1175 6: 1194 7: 711 8: 567 bogomips: 44851
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
Graphics:
  Device-1: Intel TigerLake-LP GT2 [Iris Xe Graphics] vendor: Hewlett-Packard
    driver: i915 v: kernel ports: active: eDP-1
    empty: DP-1, DP-2, DP-3, DP-4, HDMI-A-1 bus-ID: 0000:00:02.0
    chip-ID: 8086:9a49 class-ID: 0300
  Display: x11 server: X.Org v: 1.21.1.3 driver: X: loaded: modesetting
    unloaded: fbdev,vesa gpu: i915 display-ID: :0 screens: 1
  Screen-1: 0 s-res: 1920x1080 s-dpi: 96 s-size: 508x285mm (20.0x11.2")
    s-diag: 582mm (22.9")
  Monitor-1: eDP-1 model: Samsung res: 1920x1080 hz: 60 dpi: 166
    size: 294x165mm (11.6x6.5") diag: 337mm (13.3") modes: 1920x1080
  OpenGL: renderer: Mesa Intel Xe Graphics (TGL GT2) v: 4.6 Mesa 22.0.5
    direct render: Yes

[voxspox]

Hi,

I have the same problem. After upgrade to Mint 21 my screen does not go black anymore even stepping down to 0% with the brightness keys.

/sys/class/backlight/intel_backlight/brightness is when 30
max_brightness is 1500
If I set brightness to 0, then the screen is black. Somehow the brightness keys do not work then to light it up again. Had to type blindly...

Dell XPS 15 Laptop.

[jerume]

Exact same issue here, on a razer blade stealth 13.

[jerume]

No solution?

[JosephM]

Cinnamon intentionally does not allow turning the brightness down all the way to 0 with the brightness settings and keys. If you want different behavior you really should post this on the Cinnamon github. I know the decision was made because the devs thought there was no reason to allow this.

[Pjotr]

Cinnamon intentionally does not allow turning the brightness down all the way to 0 with the brightness settings and keys. If you want different behavior you really should post this on the Cinnamon github. I know the decision was made because the devs thought there was no reason to allow this.

And right they were, in my opinion.... An inexperienced user might accidentally reduce brightness to zero and then have trouble reverting this.

[jerume]

Thank you for your answers guys. Maybe you know another way, a better way, to listen an audio file without the light of the screen being turned on?

[jerume]

Code: Select all

bash -c 'sleep 0.1 && xset dpms force off'

[chrlyclsj]

Create a shortcurt with this code :

Code: Select all

bash -c 'sleep 0.1 && xset dpms force off'

But yeah, that's not really cool since it's often needed to turn a screen completely black to listen to some music, to watch a movie on a projector, and so on.

Did anyone found a way to set the minimal brighness back to a real zero ?

[Sinnis250]

Please see the second post in the thread I made earlier in '22, asking a similar question.

viewtopic.php?p=2215972#p2215972

I assigned key bindings to the Ctrl and F5 (to black screen) Ctrl and F6 (restore normal state) with this combo.

You can still dim and brighten the screen with the F5 and the F6 buttons, but as a bonus you can turn the screen off/on.

[jerume]

thanks

[SMG]

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