Re: Monitor switched off after resume from hibernation

[solitone <solitone@mail.com>]

On Friday, January 6, 2017 9:52:13 PM CET David Wright wrote:
> in your terminal, you'll probably find that
> $ echo $DISPLAY
> will give you :0 (locally) or localhost:10.0 (if you ssh into
> another computer). So your terminal's xset command will be
> happy without -display as it's got $DISPLAY instead.
> [...]
> I'm assuming that a systemd command that suddenly pops up from nowhere
> will not have a suitable value for $DISPLAY.

OK, I see.

I've ssh'd into the computer with the screen issue, and done some additional 
tests. I can switch off and on the monitor from ssh with the following 
commands ($DISPLAY is not set in shh):

$ xset -display :0 dpms force off
$ xset -display :0 dpms force on

So, I turn the monitor off, hibernate, and resume, and I get the usual black 
screen. The system is up and running, as I can ssh into it. From ssh I give:

$ xset -display :0 dpms force on

but nothing happen. Even if I try:

$ xset -display :0 dpms force off
$ xset -display :0 dpms force on

nothing happens either.

So the behaviour I have from ssh is similar to what I get from a systemd 
script. The system is apparently up and running, but I can't turn the monitor 
on, neither from systemd, nor from ssh. Funny thing!