Arch Linux

romeo-72

Member

Registered: 2024-12-07

Posts: 3

kde Plasma freeze after login

ddcutil (2.2.3-1 -> 2.2.5-1) make kde plasma freeze after login. I rolled back and added ddcutil to pacman ignore pkg.

IcePik

Member

From: Canterbury, UK

Registered: 2008-12-14

Posts: 33

Re: kde Plasma freeze after login

Thanks, this fixed the plasma freeze issue for me.

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IcePik

sgoth

Member

Registered: 2024-10-10

Posts: 4

Re: kde Plasma freeze after login

I "fixed" it by downgrading powerdevil (6.5.5-1 -> 6.5.4-1) - but ddcutil could also be it.
Did you get a lot of "permission denied" spam for R/W acces to i2c devices?

KindJ

Member

Registered: 2026-02-05

Posts: 1

Re: kde Plasma freeze after login

Thanks, downgrading ddcutil to 2.2.3-1 also fixed the plasma freeze issue for me.

Jst4Ne

Member

Registered: 2024-01-12

Posts: 4

Re: kde Plasma freeze after login

Did you get a lot of "permission denied" spam for R/W acces to i2c devices?

Yes, that indeed happened.

I would also like to add that this error only happens on internal laptop screen, on external over hdmi, there is no crash.

My hypothesis was that internal screen PSR is in some kind of contention with ddcutil making some requests, which caused freeze. Because if I disable the PSR on internal screen (amdgpu.dcdebugmask=0x10 kernel parameter) the freeze problem is gone.

As I am sure is the case with the rest of you, on my system ddcutil got upgraded as part of powerdevil upgrade.

Im on integrated amd gpu laptop, wayland, kde.

Last edited by Jst4Ne (2026-02-05 12:05:07)

sgoth

Member

Registered: 2024-10-10

Posts: 4

Re: kde Plasma freeze after login

I got the issue both with only the builtin laptop screen and attached monitors.
It even works for a few moments when i (un)plug screens. But even rebooting with only the laptop screen stopped working as soon as the sddm login completed.

Builtin screen started working again with only a powerdevil downgrade but as soon as i attached my monitors it broke again.
Since downgrading ddcutil to 2.2.3 (and upgrading powerdevil to 6.5.5 again) everything seems to work fine.

mcloaked

Member

From: Yorkshire, UK

Registered: 2012-02-02

Posts: 1,336

Re: kde Plasma freeze after login

Thank you for posting this - I had the same issue on one laptop ( Acer Swift 16) with AMD cpu and gpu. The ddcutils downgrade fixed it for this machine.

Looks like upstream report is https://github.com/rockowitz/ddcutil/issues/581

Last edited by mcloaked (2026-02-05 16:57:49)

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Mike C

nexusxe

Member

Registered: 2026-02-05

Posts: 1

Re: kde Plasma freeze after login

Also relevant:
https://gitlab.archlinux.org/archlinux/ … -/issues/5

kopperl

Member

Registered: 2026-02-05

Posts: 1

Re: kde Plasma freeze after login

Thanks that also worked for me.

Erus_Iluvatar

Wiki Admin

Registered: 2010-04-01

Posts: 136

Re: kde Plasma freeze after login

There is a alternative solution instead of downgrading that was added to the Wiki today FWIW.

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I'm french, sorry for any mistakes in english.

romeo-72

Member

Registered: 2024-12-07

Posts: 3

Re: kde Plasma freeze after login

Workaround: it seems that ddcutil 2.2.5 is in conflict with asusctl, so in order to upgrade ddcutil 2.2.3->2.2.5 it is necessary:
1. remove asusctl rog-control-center;
2. perform the upgrade of ddcutil 2.2.3->2.2.5;
3. reinstall asusctl rog-control-center.
Everything will be fine...until the next ddcutil upgrade...

mcloaked

Member

From: Yorkshire, UK

Registered: 2012-02-02

Posts: 1,336

Re: kde Plasma freeze after login

With the new Arch Linux package ddcutil 2.2.5-2 that has
git revert -n 642ddd5 316fcb9

My system no longer has the plasma freeze problem.

It doesn't look like the upstream bug has implemented this yet for the source on github.

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Mike C

mcloaked

Member

From: Yorkshire, UK

Registered: 2012-02-02

Posts: 1,336

Re: kde Plasma freeze after login

The upstream dev has been working on commits in branch 2.2.6-dev. The current dev version upstream resolves the Plasma freezes for me, and hopefully with further tests other users are doing on their machines to confirm the regression is resolved, a new fixed version will be hopefully released before long and lead to the next arch version with the regression resolved. The diagnostics and discussion is on the upstream bug report link referred to earlier.

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Mike C