Display doesn't return from being turned off sporadically

Help
1

This is a sporadic but repeated problem: I have a three monitor setup running KDE Plasma under Wayland. Current version is 6.7.4 for Manjaro. The monitors are my Framework 13’s built in screen and a pair of Lenovo P24h-10 16843009 monitors. The dock is a powered Icybox IB-DK4050 and the monitors are connected over HDMI.

When the laptop screen switches off after 10 minutes, sometimes one of the Lenovo monitors (the right hand one for the sake of clarity) doesn’t resume. Closing the laptop lid usually causes the monitor to start up again, but not always. Reopening the laptop lid also sometimes causes the monitor to start up again, but not always. Leaving the lib shut for a few minutes and then reopening it again will usually work, and this has improved since I started using this setup about a year ago. Sometimes unplugging the dock works, and on occasion, again, less so recently only rebooting works. Swapping the dock cables around causes it to happen to the left hand monitor so it isn’t the monitor. I can’t see any events in the logs that tally with the failure.

I found a similar issue on this forum that related to X11 but I can’t find it again and I’m not sure if it would apply to Wayland. I’ve also seen it mentioned that it could be related to the capacity of the dock. It’s not fatal, but it’s annoying as it tends to happen when I need to do something quickly. Has anyone else seen similar?

2

yeah ive had that on wayland with a dock + laptop panel sleep. for me it was usually the dock dropping the hdmi link when the lid/internal panel blanks, and kwin not re-probing that output.

stuff that helps here:

  1. set the laptop panel to never blank separately, or keep “turn off screen” longer than suspend
    1. in display settings, try unique arrangement so blanking one panel does not cascade
      1. journalctl --user -b -u plasma-kwin_wayland --since "10 min ago" right after a fail and look for drm/connector disconnect
        1. if the icybox is usb-c pd + multi-hdmi, a powered dock firmware quirk is common. swapping to a different dock or dp instead of hdmi sometimes stops it
      3. paste plasma version + whether the dead monitor still shows in kscreen-doctor -o when it fails.
3

Seeing how this is a laptop, switching to Display Port (or maybe DP through USB-C?) is probably not an option? Because that’s what ultimately fixed all my problems of a similar nature on my desktop.

4

Hmm, the dock has one DisplayPort and one USB-C, I’ll give that a try. Thanks!

5

Thanks, I’ll try and catch it next time it does it.

6

I’ve been fighting the same issue for about 4 years with my current laptop and various docks tried. I have a lenovo t15g2 with a 3080 using a lenovo or caldigit dock with samsung 50" hdmi tvs that same, any power-off would cause the display not to be seen. This looks like:

[pc]-[tb4]-[dock]-[dp]-[dp-to-hdmi-cable]-[hdmi]-[tv]

I troubleshot this a ton, but mostly the display no longer registers as present (xrandr), though shows connected to something, but never appears with proper modes until I juggle disconnecting the DP-to-HDMI adapters, the dock, rebooting the tv, or some combination of all after several attempts. At times I’ll get a generic “Nvidia 640x480” display appear that I assume the video card is trying hard to cope with whatever is there, but doesn’t even render on my 4k displays to see.

This doesn’t seem to be a linux issue, it’s more a low-level driver or electrical problem in the DP-to-HDMI conversion, or docks, or both.

Finally I got so aggravated with it I purchased specific edid-spoofers as a dp-to-hdmi active adapter so the pc/dock NEVER NOT see the displays to keep my sanity (which are extremely hard to find and expensive). This then looks like:

[pc]-[tb4-cable]-[dock]-[dp]-[edid-spoofer/hdmi-converter]-[hdmi-cable]-[hdmi]-[tv]

This helps so I can power off my tv’s when not in use and not lose my mind every morning resetting everything for a half hour. Now it’s not fixed though, as any reset of the dock, adapters, or even just at times the os glitch out, it fubars my displays and tends to lose one of the hdmi tv’s again to my frustration. I have to then spend 10 minutes restarting adapters, hard unplugging the dp cables, restarting the dock, over and over until finally something glitches and works again.

By this point, I think the problem is mostly in the DP-to-HDMI conversion. Because of the HDMI fiasco around licensing, I think most vendors opt to lean toward DP and let you figure the HDMI out, but these garbage chinese cables/adapter/docks you get today as a clone of a clone of a clone are all buggy enough to drive the DP PHY chips to glitch out. I’ve always attributed this to being probably an nvidia issue, but maybe not.

I too would love for a fix, but this is the first I’ve seen of someone describing anything quite like my situation. I think everyone else just blames the dock and goes on with life, but it’s still a very real pain I face every few weeks for years now.

7

That sounds very similar although Wayland and not X11, and you’re probably right about the DP/HDMI issue, so that’s the route I’ll go, maybe try and get a USB-C dock as the monitors support it.

8

I too have a laptop with a monitor that doesn’t always wake up from sleep. Mine is connected with a HDMI cable. Have not tried any alternatives, just put up with it!

I did wonder if it was a Plasma/Wayland thing, oddly has not happened since last KDE Linux update.

9

Interestingly, I’ve switched my laptop to CachyOS from Manjaro and the issue is happening less. I believe the Cachy devs have worked on sleep/hibernation quite a bit (among other things) so that may be related.

10

Don’t know if this will help, but I was having a similar problem and the fix was to allow Screen Locking and reset Power Settings to Default.

See what happens them, if OK readjust Power Settings if needed.