Ubuntu with USB 3.0 4K adapter


#1

I’ve troubleshot the issues with Ubuntu and this adapter (see here: http://support.plugable.com/plugable/…)

First, an update for that post - the installer now accounts for “systemctl” so it does “work” without an additional configuration needed.

The problem I have is this:

  1. sometimes the adapter doesn’t initialize. The blue light sometimes doesn’t come on after a cold boot, and other times it doesn’t come back on during a soft reboot. I can’t seem to find a pattern. What is the idea way to ensure that the USB 4K adapter always initializes?

  2. when the blue light IS on, and with the drivers installed and running, I still don’t see the 4K monitor as an option. There are no errors in syslog, and systemctl shows the service as running.

Here’s the rest of the back-story: I started with the barebones operating system and after many reboots, the screen suddenly appeared (in my Displays setting screen). I don’t know what I did/didn’t do, but it worked. So, applying what I’ve learned on the Windows side, I next went to install the video card drivers (this is an ATI Radeon HD 5570)

Once installed, I re-installed the DisplayLink drivers. This is where I am now… the blue light is on, the installation went well, there are no errors in syslog, and systemctl shows the service as running. However, the 4K display is not available.

I realize this is an unsupported configuration at the moment (Ubuntu MATE 15.04), so I’m not looking for the answer on how to fix this, I’m just looking for more information on troubleshooting. There are no errors anywhere, but yet the screen isn’t “available” to the “Displays” settings screen, or the ATI Catalyst Control Center application. The 4K monitor is not available for some reason.

So I have 2 questions:

  1. any tips or tricks to help the Plugable 4K adapter ALWAYS initialize. I’ve wasted many a reboot to have my main screen not-work, then I look under my desk to see the blue light off. Then, it takes some combination of cold and soft reboots to get the light to come back on.

  2. any advice on how else to troubleshoot the 4K monitor not being available to Ubuntu, after the ATI OEM drivers were installed? I get no errors, the blue light is oni, but the screen is not available. Where else can I look for errors?

thanks!


#2

Hi Rob,

Thanks for getting back with the update on your progress. As we mentioned in your previous post, while Plugable officially supports Linux on many of our products, we do not offer official support for Linux at this time for our USB 3.0 graphics adapters or USB 3.0 docking stations. Given that the DisplayLink driver is still very much in beta status, only officially supports Ubuntu 14.04 and DisplayLink is soliciting feedback directly I would recommend making a post in their Linux forum --> http://displaylink.org/forum/forumdis… so they can assist.

That said, the first thing that jumps out from your description of events is that you have installed the closed binary driver for your ATI/AMD card. Looking at DisplayLink’s knowledge base entry for the current known issues for the driver here --> http://support.displaylink.com/knowle… they state that “Closed source AMD/NVIDIA drivers are incompatible with DisplayLink driver. Please use open-source AMD/NVIDIA drivers instead.”

I would recommend removing the ATI/AMD closed drivers and returning to using the open source driver included with the distribution itself to see if that allows the monitor to be re-detected properly. Once the system is back is a working state, I would post in the DisplayLink forums to see if they can help determine the source of the intermittent adapter initialization issue.

Thank you,

Bob
Plugable Technologies
www.plugable.com/support


#3

Bob,

Ahh - good find! OK, I’ve reverted back and now the Plugable device seems to keep working, although it is noticeably sluggish like on Win10 (without the OEM drivers) - like a 500ms delay. Not a showstopper, but I was just trying to push the boundaries to see what I could/couldn’t get working at the moment.

Thanks again!

-Rob


#4

Hi Rob,

Thanks for getting back with the update. I’m glad the adapter is working again with the open source driver. In regard to the performance issue, I would recommend posting your experience on the DisplayLink forum I linked to earlier. As the driver is still a beta your feedback may help them improve before the first official release.

Thank you,

Bob


#5