plasma5 screen management going wrong

[Duncan]

Bug Reporter posted on Fri, 13 Jul 2018 18:52:16 -0400 as excerpted:

> However, I do not want to remove powerdevil, therefore, I cannot remove
> kscreen. I looked at laptop-mode-tools and I did not like what I saw. It
> looks very dated. I'm not confident it will work that well on modern
> hardware. For example, I'm running NVMe drives. I don't want to get
> diverted from the task at hand by having to solve a bunch of power
> management issues, so powerdevil has to stay installed -- but I want to
> disable kscreen.
> 
> In addition to KSC_XRandR11.so, which me mentioned previously, I see
> KSC_Fake.so, and that prompts a question.
> 
> # ls /usr/lib/qt/plugins/kf5/kscreen/
> total 504
> drwxr-xr-x 1 root root    136 Jun 27 12:50 .
> drwxr-xr-x 1 root root    490 Jun 20 21:45 ..
> -rwxr-xr-x 1 root root 100176 Jun 26 09:15 KSC_Fake.so
> -rwxr-xr-x 1 root root 104360 Jun 26 09:15 KSC_KWayland.so
> -rwxr-xr-x 1 root root  67408 Jun 26 09:15 KSC_QScreen.so
> -rwxr-xr-x 1 root root  75600 Jun 26 09:15 KSC_XRandR11.so
> -rwxr-xr-x 1 root root 157608 Jun 26 09:15 KSC_XRandR.so
> 
> What would happen if I copy KSC_XRandR11.so to KSC_XRandR11.so.bak and
> then copy KSC_Fake.so to KSC_XRandR11.so? I wonder if that would render
> kscreen "disabled" while leaving it installed. Any thoughts on this?

That's a very creative idea! =:^)

I hadn't noticed the fake one, but my guess is that it's there to provide 
a "fake" backend for CI/constant-integration testing, on a build/testing 
server (well, probably a VM/container these days) that very well may not 
have a real X/wayland session available to play with.  The fake backend 
would allow testing without such a session, or without messing up an 
existing session if it were available.

It's also possible it could be used for installations on other OSs, OSX 
and some of the other BSDs, and perhaps even MS Windows, where there 
might not be a direct tie-in to the native power and screen management.

Of course switching it out may not work, and if it does it'll very likely 
disable the powerdevil display management, that of course being why 
powerdevil would depend on it in the first place.  That may or may not be 
OK with you.

The only way to see is to try, but I'm guessing you're already doing just 
that. =:^)

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman