SUMMARY When PC is booted up with thunderbolt dock attached screens go blank. Unplugging and replugging the dock screens come up. STEPS TO REPRODUCE 1. Boot up system with thunderbolt dock attached and external screen 2. 3. OBSERVED RESULT Screens are blank EXPECTED RESULT Screens show show desktop SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Plasma: Neon 5.20.2 (available in About System) KDE Plasma Version: 5.20.2 KDE Frameworks Version: 5.75.0 Qt Version: 5.15.0 ADDITIONAL INFORMATION
I have two docks 1 is the dell D6000 universal the other HP thunderbolt. Heres what i figured out today - The dell D6000 will not work in 3840x2160 @ 60hz but drops back 30hz this seems to sometimes confuse kwin, repluging brings it back and will not work under wayland at all. The HP thunderbolt using DP cables runs at full 3840x2160 @ 60 hz but if booted with the unit plugged in does not turn the screen on but it 'thinks' the display is active.
Missed that repluging the thunderdock docks wakes the screen then its fine
Seeing this for 5.20.3:- Drm: Make sure the screens are turned on when we come from suspend. Commit. Fixes bug #428424 Wondering if this will fix the issue with the thunderbolt dock not turning on the display. Will see when it comes through
I received the Neon update this morning with Qt 5.15.1 and plasma 5.20.3, so far on the thunderbolt dock the screen seems to be waking up as it should will keep an eye on it
OK so testing the thunderbolt dock has revealed an improvement on X, now when my machine has a cold start or reboot the external display comes on and operates as expected. Screen can now wake after it has gone into energy saving. Next I logged out back to SDDM, it went blank opened the notebook lid and sddm came up on it. Logged into wayland and external display remained blank. But plasma sees the display as active as i loose the mouse cursor off the screen
Oh well, I left my machine running a while, screen was asleep and it would not wake up again, I guess unfortunately its not fixed
IS there anything you want me to do to help to trace this?
Thank you for the bug report. Unfortunately we were not able to get to it yet. Can we ask you to please check if this is still an issue with Plasma 5.25 or 5.26? If it is, please change the status to CONFIRMED when replying. If not, or if you can't because you no longer use this setup, you can change the status to RESOLVED WORKSFORME. Thanks a lot!
I dont have the same setup anymore and have not struck this with the Thunderbolt dock I am currently using so I am comfortable saying RESOLVED WORKSFORME