Comment 75 for bug 1295267

Revision history for this message
Ben (bi613en) wrote :

Below is a fix/workaround/solution that might work for some who are visiting this thread.

Short version:
Stop using external video adapters and instead use the natively supported connections.

Medium version:
Ubuntu 14.04 _AND_ 16.04. My problem started when I started using a external video adapter (hpk-481409-001 Displayport to DVI). It was solved by ceasing to use the video adapter and instead using the native connections of both the monitor and PC.

Long version:
I was running 14.04 on an HP Elitedesk 800 workstation with 2 Display ports and 1 VGA port. I changed monitors and needed to start using an adapter for one of them since they only supported DVI input, the display ports on the PC were internally connected in parallel, and the Display port to DVI cables that I had only mapped the first channel. When the problem started, I thought that it was an Ubuntu update issue and it would resolve itself. I later upgraded from 14.04 to 16.04 and the problem persisted. I tried switching to a heterogeneous monitor configuration like I had before the monitor change, because I thought that it might be a monitor-name identification issue, however this did not fix the problem. I tried using a VGA/Displayport combination (luckily for those reading this I, for some reason, kept the displayport-DVI-adapter connection), and that didn't solve the problem. Then, I simply replaced the displayport-DVI-adapter connection with a simple displayport-DVI cable, and I do not see the problem anymore. If it pops up again I will provide an update.