[Pkg-xfce-devel] Bug#788668: Bug#788668: light-locker: Black screen(not powered on) after unlocking screen locked by closing the laptop lid

Valdaer valdaer at gmail.com
Tue Jun 16 02:49:08 UTC 2015

On 14.06.2015 16:22, Yves-Alexis Perez wrote:
> On dim., 2015-06-14 at 05:16 +0200, valdaer wrote:
>> Package: light-locker
>> Version: 1.6.0-2
>> Severity: important
>> Dear Maintainer,
>> When screen is locked triggered by closing the laptop lid then when 
>> user enters
>> password in light-locker screen goes black(powered/switched off). 
>> When screen
>> is locked not triggered by the closing lid event(for example xflock 
>> command
>> triggered by keyboard shortcut) screen unlocking is working fine 
>> tough.
>> I was thinking that this is a xfpm/systemd bug similar to this one:
>> https://bugzilla.xfce.org/show_bug.cgi?id=10535 but then I installed
>> Xscreensaver for a test and it was working fine so I presume this is 
>> most
>> probably light-locker bug.
>> On the other hand I was using light-locker before(1.4.0-1 version) 
>> and it was
>> working fine but it was at the time when testing was freezed and I 
>> had previous
>> versions of xfpm and systemd(don't remember exacly which versions). 
>> When I've
>> reverted the light-locker package to 1.4.0-2+b1 version but it didn't 
>> help.
>> I've also tried to verify that this issue exist without using xfpm 
>> too but
>> couldn't trigger lock screen by laptop lid through systemd/logind 
>> because of
>> this bug: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=741491
>> The workaround that I am using for this issue is "xrandr --auto" 
>> command saved
>> to some keyboard shortcut taken from this bugtopic:
>> https://bugs.launchpad.net/ubuntu/+source/xfce4-power
>> -manager/+bug/1259339
>> however it is very annoying to do this every time when opening laptop 
>> lid and
>> it does mess external monitor sometimes.
>> I didn't notice anything extraordinary in journalctl logs, when I 
>> will find
>> time I will try to enable some debug options in light-locker/light-
>> dm/systemd/xfpm if these are easy to set.
> Hi,
> can you try the light-locker package at 
> http://perso.corsac.net/~corsac/debian/xfce4/ ?
> You can pick the .dsc and rebuild it, or use the .deb directly (the
> .changes file is signed by my key).
> Regards,

Hi, thx for quick answer, unfortunately light-locker version from your
repo was working same as one from testing and didn't solve the problem.

I drilled down the problem a little bit and it turns out that this could
be caused by dependencies of light-locker, lightdm and systemd because
lightdm uses VT switching to operate and systemd/logind inhibitors are
by design per VT. Even if the aformentioned reason isn't a root cause
for this it is causing other issues and this bug is called infamous
blank-screen-after-unlock bug on xubuntu bugtracker.

I've managed to find(mostly through this topic:
that there is a separate lid-closed branch in upstream repo:
https://github.com/the-cavalry/light-locker/tree/lid-closed which is
there from quite some time and I don't know why it isn't merged to master.

Anyway I installed the light-locker packaged from Ubuntu repo
http://packages.ubuntu.com/vivid/x11/light-locker(most probably patched
version from lid-closed branch but I haven't investigated it yet, only
saw new light-locker option added in one of the commits in that branch)
and this bug haven't occurred to me anymore.

I think Debian should ship patched version too. I can package it, wanted
to get involved in Debian development anyway, but it will take a while
until I will make my setup(I've only watched some packaging tutorials).
I know that as a main Xfce Debian maintainer you have much to work but
if you would manage to find some time for this it would be nice, I'm
sure there are some more laptop users using Xfce with light-locker on
debian annoyed by this bug.

Sławomir Wójcik

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