Adaptive Backlight Management help or Why I (sometimes) hate the linux desktop

Hi,
I’m running Bluefin-dx F42 on a Lenovo ThinkPad T14 Gen 2 with an AMD Ryzen 5 PRO 5650U (Radeon Graphics). When I set the power profile to “power saver”, the system enables Adaptive Backlight Management (ABM) to reduce power usage. While this can save up to ~1 watt by dimming the backlight and tweaking contrast, it significantly degrades color quality—everything looks washed out and dull.

I could tolerate this behavior while running on battery, but the issue is that ABM is also active when the laptop is plugged in (and in power-saver profile).

I came across a possible workaround here:

However, I’m not confident whether this solution is applicable to Bluefin.

Now why do I hate the linux desktop for this? This feature was introduced a few months back after a regular update. Overnight, the display contrast dropped, and for days I assumed it was a hardware fault. I still cannot enjoy a movie or see a family photo (with proper colors) on the laptop screen without setting the power profile “High performance” and have the fan output tons of heat and noise.

I’d really appreciate any feedback. Thanks

you can set the kernel args to override this setting if you want.

  • abmlevel (uint)

Override the default ABM (Adaptive Backlight Management) level used for DC enabled hardware. Requires DMCU to be supported and loaded. Valid levels are 0-4. A value of 0 indicates that ABM should be disabled by default. Values 1-4 control the maximum allowable brightness reduction via the ABM algorithm, with 1 being the least reduction and 4 being the most reduction.

Defaults to -1, or auto. Userspace can only override this level after boot if it’s set to auto.*

But this affects only the powersave level, so balanced (which is the general recommended setting) is not affected by this

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Hi, thanks a lot for the response.
I don’t have any experience setting kernel args. Could you provide a few more details on how to implement your solution?

If you want to disable it completely you can do:

rpm-ostree kargs --editorand at the end of the line add:

amdgpu.abmlevel=0

or you can try different leves from 0 (disables it all together) to 4

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