[CLOSED] Screen turns back on after screensavor activates

[SunriseYawning]

I would simply like to make things clear, if you don't mind. Worst, I don't have answers, I just have questions:

I don't mind one bit. Like I said, it's an annoyance, but one that is growing on me. The biggest annoyance is when I switch to my work laptop and switch monitor inputs. When my work laptop sleeps, the screen revert back to Linux Mint, requiring me to manually move the inputs back to my work laptop, like some sort of heathen.

I've replied to your questions in-line:

• The Power Manager sends some DPMS command, right? After counting 5 or 15 minutes or more, it sends a xset dpms force off or "standby" or "suspend", I don't know what exactly...
  - I believe so? I'm not familiar with what Power Manager does exactly. I assume there is a service that will issue the appropriate xset command after a given time.
• You also tried with that CLI and it works, at first, but the screen wakes up after a few minutes. Did I understand your OP correctly?
  - yes, tried with the CLI but screen wakes up after a few *seconds*, not minutes.
• Does it also works with the GUI, when you set the power manager to turn off the screen when inactive for 5 minutes? Yes, the screen is back on after a few minutes, but did it work, at least for a few seconds?
  - Yes, screen turns off, and then after a few seconds it turns back on. The screen turning off behavior is inconsistent at best.

[sebastjava]

Thanks for that quick and precise reply. So, to sum up, both the GUI and the CLI are working, but only for a few seconds. "The screen turning off behavior is inconsistent, at best."

Well, yes, I would do this simple test here. I would unplug both the keyboard and the mouse. I added a 60 seconds delay, so you get enough time to do that:

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bash -c "cinnamon-screensaver-command -l; sleep 60; xset dpms force off;"

(The USB is a "Hot-Plug", it can be disconnected and reconnected while everything is powered on without causing any damage.)

[SMG]

The biggest annoyance is when I switch to my work laptop and switch monitor inputs.

How are you switching to your work laptop? Are you using a KVM?

[SunriseYawning]

Well, yes, I would do this simple test here. I would unplug both the keyboard and the mouse. I added a 60 seconds delay, so you get enough time to do that:

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bash -c "cinnamon-screensaver-command -l; sleep 60; xset dpms force off;"

Screen turned off after a minute and then turned back on after roughly 10 seconds.

(The USB is a "Hot-Plug", it can be disconnected and reconnected while everything is powered on without causing any damage.)

Thanks for the reminder. Just to level-set appropriately, I'm very experienced in IT. I'm quite familiar with USB. I'm just not an expert in Linux Mint specifically. Though, tbh, if this were happening on Ubuntu, I think I'd be just as lost.

How are you switching to your work laptop? Are you using a KVM?

Nothing that fancy. I have my keyboard and other peripherals on a USB hub. I manually move the hub USB to my work laptop's docking station. The monitors have a total of four inputs: VGA, DisplayPort, Mini DisplayPort, and HDMI. The DisplayPort on both monitors are directly connected to my work laptop's docking station. HDMI and MiniDP are then directly connected to my Linux Mint Desktop.

I know that DisplayPort KVM switches exist but can't justify spending $200+ on something that would provide little value to me.

[SMG]

The monitors have a total of four inputs: VGA, DisplayPort, Mini DisplayPort, and HDMI. The DisplayPort on both monitors are directly connected to my work laptop's docking station. HDMI and MiniDP are then directly connected to my Linux Mint Desktop.

So you have the monitors simultaneously connected to two different computers? Are you completely shutting down one computer before moving to the other? Or are both computers running and thus both of them are trying to control the monitors?

[SunriseYawning]

So you have the monitors simultaneously connected to two different computers? Are you completely shutting down one computer before moving to the other? Or are both computers running and thus both of them are trying to control the monitors?

I have both monitors simultaneously connected to two different computers. Right now, my work laptop is completely shut down.

During the work day, my Linux Mint computer stays online because I run various services. To say that they are both trying to control the monitors is not quite right. When I was on Ubuntu Desktop, I would lock Ubuntu, which would turn off the monitors. With my work computer on, I was free to use the monitors with it.

If I locked my work computer for lunch, or whatever, it would also turn off the monitors, leaving the monitors in a sort of "standby" mode (e.g. LED backlight off). I could, if I wanted to, switch my mouse to Ubuntu and the monitors would switch magically with no input from me. After a minute or so without input (assuming I didn't enter my password), the monitors would turn off again, allowing me to return to my work computer by switching my mouse input to it (or tapping the keyboard).

[SMG]

When I was on Ubuntu Desktop

I presume you are referring to used the Gnome desktop

I would lock Ubuntu

How were you locking it? And how are you locking it now?

You titled this topic that the screen turns back on after the screensaver activates, but the settings I am seeing for locking is that locking happen after the screensaver activates and not before the screensaver. However, that would be using default settings which may not be how you are locking.

[SunriseYawning]

I presume you are referring to used the Gnome desktop

I believe so. Whatever their default DE is.

How were you locking it? And how are you locking it now?

Super+L (Win+L) for both Ubuntu and Linux Mint

I originally remapped the Lock shortcut to Win+L but then saw that similar people had issues so I created a custom command, as I originally posted.

You titled this topic that the screen turns back on after the screensaver activates, but the settings I am seeing for locking is that locking happen after the screensaver activates and not before the screensaver. However, that would be using default settings which may not be how you are locking.

I've attached screenshots for my settings. Hopefully it will help.

[SMG]

You titled this topic that the screen turns back on after the screensaver activates, but the settings I am seeing for locking is that locking happen after the screensaver activates and not before the screensaver. However, that would be using default settings which may not be how you are locking.

I've attached screenshots for my settings. Hopefully it will help.

You have the screensaver set to come on after 15 minutes so it would seem something other than the screensaver is causing the screens to come back on because you said, "screen wakes up after a few *seconds*, not minutes." Others have used the same command as you are using and have not mentioned the screens coming back on.

Did you check to see if DPMS is showing as enabled for your monitors? What is the output of

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xset -q

I found this forum post that seemed related: I'm using DisplayPort and HDMI for two screens. But the problem occurs even when I use one display.

In that case, the HDMI port was the issue with that GPU and that person found out that:

Turns out the problem was with the HDMI CABLE (5 meters long)

I have no idea why, but that particular cable kept waking the screens up from DPMS mode.

Problem is solved when using other HDMI cables (shorter ones).

I do not know enough about how GNOME works to know if there are differences in the screensaver. If you were using a recent version it is possible you might have been using Wayland rather than X Server which might be making a difference.

[SunriseYawning]

Did you check to see if DPMS is showing as enabled for your monitors? What is the output of

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xset -q

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Keyboard Control:
  auto repeat:  on    key click percent:  0    LED mask:  00000000
  XKB indicators:
    00: Caps Lock:   off    01: Num Lock:    off    02: Scroll Lock: off
    03: Compose:     off    04: Kana:        off    05: Sleep:       off
    06: Suspend:     off    07: Mute:        off    08: Misc:        off
    09: Mail:        off    10: Charging:    off    11: Shift Lock:  off
    12: Group 2:     off    13: Mouse Keys:  off
  auto repeat delay:  660    repeat rate:  25
  auto repeating keys:  00ffffffdffffbbf
                        fadfffefffedffff
                        9fffffffffffffff
                        fff7ffffffffffff
  bell percent:  50    bell pitch:  400    bell duration:  100
Pointer Control:
  acceleration:  2/1    threshold:  4
Screen Saver:
  prefer blanking:  yes    allow exposures:  yes
  timeout:  0    cycle:  0
Colors:
  default colormap:  0x20    BlackPixel:  0x0    WhitePixel:  0xffffff
Font Path:
  /usr/share/fonts/X11/misc,/usr/share/fonts/X11/Type1,built-ins
DPMS (Energy Star):
  Standby: 0    Suspend: 0    Off: 0
  DPMS is Enabled
  Monitor is On

I do not know enough about how GNOME works to know if there are differences in the screensaver. If you were using a recent version it is possible you might have been using Wayland rather than X Server which might be making a difference.

I don't think I was using Wayland. Pretty sure it was X...but with that said, what I can try to do is boot from an ubuntu 22 Live CD and see if it works the way I expect.

[SMG]

I don't think I was using Wayland. Pretty sure it was X...but with that said, what I can try to do is boot from an ubuntu 22 Live CD and see if it works the way I expect.

When you boot it, let us know the inxi output (you might have to install inxi) of

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LANG=C inxi -Fxxxrzc0 --usb

I am out of new ideas.

[sebastjava]

I am out of new ideas.

In the worst case, if nothing works, please remind me to tell you about xrandr. I think you could create a keyboard shortcut to turn off your screen in a more radical way than with DPMS... Something similar to the shortcut you already had created: lock the screen, and then turn it off. Radically.

But be careful! When you switch off the output to a monitor using xrandr, it won't turn back on when you touch your keyboard or mouse! So, you need to make sure you also create a keyboard shortcut to turn it back on! Else, you could need to force your computer to power off and then back on to reset everything...

[SMG]

I am out of new ideas.

In the worst case, if nothing works, please remind me to tell you about xrandr. I think you could create a keyboard shortcut to turn off your screen in a more radical way than with DPMS... Something similar to the shortcut you already had created: lock the screen, and then turn it off. Radically.

I am not the OP and you already posted about that in this topic.

[sebastjava]

I am not the OP and you already posted about that in this topic.

About xrandr? In this topic? No, I didn't mention that before. Search for xrandr using Firefox, you won't find it here.

[sebastjava]

Ah, okay, sorry, I did reference it before, with a link... But I did not really give much details...

Else, if you really want to make things more complicated and mess up with your system, then follow my nice little tutorial here: viewtopic.php?p=2437772#p2437772

[SunriseYawning]

It looks like a live ubuntu USB isn't going to cut it. Lock is disabled for some odd reason.

I'll admit, I'm at the point of giving up myself. Short of diving head-deep into the power management settings, I'm at a loss of why it's happening.

Should I mark this thread "Solved"?

[sebastjava]

I'll admit, I'm at the point of giving up myself.

Well, if we are running out of time before you close this topic, then I have to throw in my thoughts, at the high risk of looking a bit stupid...

Primo. I would be curious to see if you still get this problem when you only have one computer plugged to the monitors. Disconnect your job's laptop from all the screens, or just do a complete shutdown, and have only Linux Mint running. Then do your combination of screen lock plus DPMS. Using either screensaver + power manager, or your custom CLI. I bet everything works fine when you only have Linux Mint connected to these monitors. Thanks to SMG for suggesting this idea to me. I bet you both had already thought of this, but I didn't see any echo of it...

Secundo. My xrandr custom solution may look a bit crazy, but I am confident it could work. But that would be a long story. Maybe I will take the time to write about this later, if you don't change the title to (SOLVED) or (CLOSED)...

[sebastjava]

Please post the output from:

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xrandr --listactivemonitors

[SMG]

It looks like a live ubuntu USB isn't going to cut it. Lock is disabled for some odd reason.

I have no guesses why that might be.

Should I mark this thread "Solved"?

Topics remain open for six months after they are created. If you decide you no longer want help on this issue, I suggest marking it [CLOSED] rather than solved because we have not figured out why it is happening.

[sebastjava]

It looks like a live ubuntu USB isn't going to cut it. Lock is disabled for some odd reason.

I have no guesses why that might be.

I would suggest a very simple answer... Case example:

It is a live session. I am a newbie. I don't know the username and password for this live session. I am running the installer, everything went fine, it will be all done in approximately 2 minutes. Oops, now what!? Oh, I had the screensaver set to start and lock after 15 minutes. So now, I am locked out of this live session, while the installer is still working, and I just don't know how to get back in.

I think this really happened to me once or twice, a few years ago... Yes, if I remember correctly, the username is "mint", and the password is "" (nothing). But I didn't know back then.