Hi there, I am a really happy KDE Neon almost since it came out but ever since have had issues with my dual monitor setup. This is starting to get unbearable so I am looking for help.
I am running a Dell Precision 7510 laptop with a docking station with two HDMI and Display Port connected monitors.
Software is KDE Neon User edition with all updates released until today..
Native Ubuntu Nuvoau graphic drivers
Intel graphics

First of all, when it works it works! Both screens will show what I want, layout, resolution, everything's fine.
But every now and then when I put the laptop into the docking station one of the screens will simply stay black.
Whenever that happens I will go through my usual trouble shooting routine:
- Reboot docked
- Reboot undocked and dock afterwards
- Put the machine to sleep and wake it up docked
- Unplug monitors / power cycle
- Try several xrandr options to wake it up
- Whatever I can think of, nothing scientific...

An interesting fact is that while the machine is starting it will most of the time show the KDE logo + version on both screens and at some point one of the screens would turn black and turn itself off. Sometimes the KDE logo / version screen would stay on on one screen while the second one is already showing the KDE desktop, eventually it'll switch itself off though.

However, most of the times one of the actions above will get me back to a working setup.
A few months ago though nothing worked which ultimately led to a system which wouldn't start into graphical mode at all (because of the constant reboot/undock/dock trials) which I didn't manage to fix which meant I had to reinstall.

After the new install I had a setup where in case of issues, I was reliably able to get to my second screen as long as I made sure the machine was already running when I put it into the docking station with lid closed. After waking it up I would receive the logon screen on both screens, type in my password (without an screen response because for some reason no cursor and "*" are displayed, during log on and off I go.
In other words, whenever I got the the black background logon screen things won't work, blue background will work. Not sure but I think black is shown after a fresh start and blue when someone logs in to an already running system?

Long story short, it looks like today is another day where nothing seems to work. This time though the second screen started of all white with some "noise", a few reboots later it turned to the usual all black.

If anyone has got an idea how to troubleshoot, force the system to reset it's graphics settings or even better save a working configuration and to force apply again in case needed I'd be grateful.

Thanks
Thomas

Could you post the output of:

Code: Select all

lspci -k |grep VGA -A2

Absolutely! Here you go:

$ lspci -k |grep VGA -A2
00:02.0 VGA compatible controller: Intel Corporation Skylake Integrated Graphics (rev 06)
DeviceName: Onboard IGD
Subsystem: Dell Skylake Integrated Graphics
--
01:00.0 VGA compatible controller: NVIDIA Corporation GM107GLM [Quadro M1000M] (rev a2)
Subsystem: Dell GM107GLM [Quadro M1000M]
Kernel driver in use: nouveau

I wrote a little script a while ago which runs a few similar commands as I was hoping to help me identify my issue. So far it didn't help but maybe you can read some more into it.
This is the output of a failing setup : https://www.dropbox.com/s/cnkloowjnnq46 ... g.txt?dl=0
This is the output of a working setup: https://www.dropbox.com/s/7q2ze6gwv6prf ... g.txt?dl=0
Right now it's the DELL screen which is failing. You can find it's details in the text files.

And finally a screenshot of what the situation looks like:
Started off with a white screen this morning: https://www.dropbox.com/s/rze3xbrc2cw8v ... e.jpg?dl=0
Went to black after a few attempts: https://www.dropbox.com/s/2quknyiwlo1w2 ... k.jpg?dl=0
And right now I have it white again...
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Edit:
Thought I'd add a few more pictures for illustration:
The situation this morning is that Neon will start up with showing Logo and version on both screens
https://www.dropbox.com/s/2io0yup8c27k5 ... s.jpg?dl=0

A few seconds later the screens will be out of sync. The failing one still shows the KDE logo, the working one the logon screen
https://www.dropbox.com/s/wm6iqr2sfbohl ... c.jpg?dl=0

Finally the failing monitor gives up and goes into sleep mode
https://www.dropbox.com/s/189mqii8uu6jh ... f.jpg?dl=0

Not sure if it's relevant but when I type in the password it won't show anything on the screen, none of the usual **** will appear in the password field. But I will get to my desktop just fine after I hit enter.
-------

Thanks a lot for looking into this!
Thomas

Hm, I have no experience with dual graphic cards. However, I've got three monitors on my single card and every now and then it refuses to start one or the other or doesn't place it where I want. My solution is a simple restart of X although I have not played with krandr yet.

I can only recommend that you read https://wiki.archlinux.org/index.php/Hybrid_graphics and https://wiki.archlinux.org/index.php/Multihead and identify which graphic card is responsible.

HTH

Thanks for getting back.
I have now given up and switched from Neon to Kubuntu in the hope that maybe one of the 18.04 components fixes my issues. So far so good, both screens are working again.

Thanks
TZ