Bug 499733

Summary:	Review and deal with p-p-d configurable actions
Product:	[Plasma] kwin	Reporter:	Jakob Petsovits <jpetso>
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	CONFIRMED ---
Severity:	task	CC:	nate, xaver.hugl
Priority:	NOR
Version First Reported In:	git master
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Jakob Petsovits 2025-02-10 01:36:14 UTC

SUMMARY
Mario Limonciello has merged his patch for power-profiles-daemon to allow enabling or disabling power actions, and added AMD GPU actions that are disabled by default. This change will be part of the 0.24 release once it comes out.

Two links into the MR that seem relevant to us:

- https://gitlab.freedesktop.org/upower/power-profiles-daemon/-/merge_requests/210/diffs#note_2768758
- https://gitlab.freedesktop.org/upower/power-profiles-daemon/-/merge_requests/210/diffs#8ec9a00bfd09b3190ac6b22251dbb1aa95a0579d_58_58

Specifically, he mentions that he expects desktop environments to expose the actions "amdgpu_dpm" ("Adjust GPU dynamic power management") and "amdgpu_panel_power" ("Panel Power Savings (may affect color quality)") to users. Those make for a bad default experience, but could be right for an informed user who prefers battery life over fidelity.

We already have a "Prefer efficiency" vs. "Prefer color accuracy" setting in the Display Configuration KCM, I don't know how that would interact with these new settings.

Filing as bug for awareness at least until the KWin team determines what to do (or what not to do) about it.

Comment 1 Zamundaaa 2025-02-10 14:02:55 UTC

Sigh, panel power savings was supposed to be a drm property again, and not stay something another process controls through a backdoor :/
I don't think we should bother with it until that changes, and until we can do anything about it without having to drag dbus into the output configuration system...

> Adjust GPU dynamic power management
I think that's something we could put into the power management settings though. Afaiu it just makes the power saving mode more aggressive on the GPU, that should be relatively straight forward, UX wise.

Comment 2 Jakob Petsovits 2025-02-10 15:41:56 UTC

(In reply to Zamundaaa from comment #1)
> Sigh, panel power savings was supposed to be a drm property again, and not
> stay something another process controls through a backdoor :/
> I don't think we should bother with it until that changes, and until we can
> do anything about it without having to drag dbus into the output
> configuration system...

My naive reading is that it's still a DRM property:
https://gitlab.freedesktop.org/upower/power-profiles-daemon/-/blob/c47fea05d439a69c6a53d4c4e02c56bd8ca51200/src/ppd-action-amdgpu-panel-power.c#L291

As long as p-p-d doesn't mess with it, I guess there's no problem with you accessing it directly as opposed to letting p-p-d do it.

> > Adjust GPU dynamic power management
> I think that's something we could put into the power management settings
> though. Afaiu it just makes the power saving mode more aggressive on the
> GPU, that should be relatively straight forward, UX wise.

Yeah, that's worth considering. One hiccup for UX is that p-p-d applies this option (and others) based on its "power-saver" profile being active, rather than the AC / Battery / Low Battery / Critical Battery split that we use in Power Management settings.

On a tangential note, I also noticed that the "trickle_charge" action is enabled by default and is going to mess with my efforts to get custom charge thresholds working for Dell laptops (https://invent.kde.org/plasma/powerdevil/-/merge_requests/510). Also sigh.

Comment 3 Zamundaaa 2025-02-10 15:58:40 UTC

(In reply to Jakob Petsovits from comment #2)
> My naive reading is that it's still a DRM property:
> https://gitlab.freedesktop.org/upower/power-profiles-daemon/-/blob/
> c47fea05d439a69c6a53d4c4e02c56bd8ca51200/src/ppd-action-amdgpu-panel-power.
> c#L291
No, it's exclusively a sysfs file. The drm property was removed.