Problems with Redshift and brightness of screen

[soorg]

LXQt 64bit (x86_64/amd64) 2020.12

Some time ago I installed the Redshift program. It's a good program which cares about your eyes ('Adjusts the color temperature of your screen.')

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sudo apt-get update
sudo apt-get install redshift

I registered the program in LXQT Autostart like:

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/usr/bin/redshift -l 52.44167:31.00000 -t 6500:4500 -b 0.8:0.7

...and it worked very well until the update a couple of days ago. Then everything went wrong. Now the screen is just flashing at a frequency of 2 seconds -bright/dim.

So I've decided to turn redshift from Autostart off and check it through the terminal:

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xxxxx@xxxxxxx:~$ redshift -l 52.44167:31.00000 -t 6500:4500 -b 0.8:0.7
Could not connect to wayland display, exiting.
Failed to start adjustment method wayland.
Trying next method...
Using method `randr'.
Waiting for initial location to become available...
Location: 52.44 N, 31.00 E

The screen is just flashing. By the way, the brightness settings doesn't work either. It resets to full (100%) brightness.

[paxmark1]

I do not see anything at  the BTS

https://bugs.debian.org/cgi-bin/pkgreport.cgi?dist=unstable;package=redshift

[soorg]

Sorry, paxmark1. I don't follow. Should I leave there some cool  bug report or what?

[paxmark1]

No,  Since you are in Sparky they do not want bugs filed unless from a standard debian install.   That simplifies things immensely for them.

It is just one of my first places I look when I have problems with a specific program(s).     Unstable had 5 days minimum to come up with big bugs.  IIRC you are in rolling - which is testing for Debian.   Doing this lets you know that the probability of it being a problem with the redshift program is less.

Via looking at the change log
https://metadata.ftp-master.debian.org/changelogs//main/r/redshift/redshift_1.12-2_changelog

you can see that it has not  been upgraded in almost two years.   

This would lead me to suspect it is a LXQT thing.   I do not know if a new Debian maintainer has been found for LXQT.   Alf G. has not posted at Siduction or made changes at LXQT for awhile.  I am in Stable LXQT.   My suggestion if no one else posts is to look at the LXQT bug page.  Also there is the LXQT irc channel.   A bit of a learning curve for irc  (Internet Relay Chat).   

[paxmark1]

Something caught my eye in your code in your first post (Thank you for posting code)

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xxxxx@xxxxxxx:~$ redshift -l 52.44167:31.00000 -t 6500:4500 -b 0.8:0.7
Could not connect to wayland display, exiting.
Failed to start adjustment method wayland.
Trying next method...
Using method `randr'.
Waiting for initial location to become available...
Location: 52.44 N, 31.00 E

LXQT was very hopeful at becoming Wayland compliant (at least some of them) 2 or more years ago.   That hope is much dimmer - it is in the

https://github.com/lxqt/lxqt/issues/10

That might be the problem.   I am not an expert at Xorg or xrandr.      The Arch linux has a really good wiki and search engine, but do not ever follow it blindly.  putting "randr" into yields a few hits in Russian and Chinese that also mention redshift  and a English version

https://wiki.archlinux.org/index.php/Redshift

Redshift makes the screen quickly flicker between the set color value of the screen and the default color value

Make sure there are not multiple instances of redshift running.

Hopefully I am not sending you off on a wild goose chase.   Maybe wiser people will post.   

[soorg]

Thanks, paxmark1, for your extended response.
Hmm... I guess, I've just found some crutch-'elegant' solution of my issue.

If I/we encounter this:

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xxxxx@xxxxxxx:~$ redshift -l 52.44167:31.00000 -t 6500:4500 -b 0.8:0.7
Could not connect to wayland display, exiting.
Failed to start adjustment method wayland.
Trying next method...
Using method `randr'.
Waiting for initial location to become available...
Location: 52.44 N, 31.00 E

...the program itself is able to suggest something like this:

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xxxxx@xxxxxxx:~$ redshift -m list
Available adjustment methods:
  wayland
  drm
  randr
  vidmode
  dummy

What should I choose? I'm sure Wayland (if it exists on my computer) does not work correctly because I have some tearing while browsing.
So I took the more deprecated method of adjustment called 'vidmode' and it worked out!

Finally through LXQT Autostart it looks like:

/usr/bin/redshift -l 52.44167:31.00000 -t 6500:4500 -b 0.8:0.7 -m vidmode

[paxmark1]

Glad to see you taking charge and investigating.   I have never been much into the fine points of Xorg.    I did like Wayland in that I had few problems with it, but I was using a Tiling manager (Sway - the port of I3) and have not used redshift (although it does seem a good idea).   If no replies here I would suggest posting at the LXQT irc    OFTC #lxqt

Via Debian Forum   searches redshift    redshift lxqt  (0) and redshift  wayland

http://forums.debian.net/viewtopic.php?f=10&t=144818&p=713418&hilit=redshift+wayland#p713418

Not anything really new, but a fair review of redshift and other similar programs in Debian 10.   If you are rolling- testing, you are in 11

LXQT  last upgrade was in Feb 2020 via Alf G.   Redshift was bumped from 1.12-3 to 1.12-4 in unstable on the 12th.   It might have entered Testing on the 17th.   If you have 1.12-4 in your machine you could bump it back to the previous version.
https://metadata.ftp-master.debian.org/changelogs//main/r/redshift/redshift_1.12-4_changelog

Probably not involved but there is the option of using xfwm4 or openbox as your window manager in LXQT.   I do not think that would make a difference.

peace out.