I am having a hard time making usbc -> DisplayPort work on my xps,
I have tried different adapters, which seems that there are people that say that it works on their machines but my screen says (No Displayport connected)
The funny thing is that I bought the same adapter than  but for HDMI output (instead of displayport) and that one works. I want to use displayport because HDMI only gives me 30Hz.
It seems to be something specifically related to the displayPort output.
Does usbc->displayPort work on the prebundled Ubuntu 14.04.4?
Do you know for sure an adapter that works?
Anything else I could try?
* I have tried with multiple screens, Dell P2815Q (4K), Dell U3014 and none of them work via displayport (they used to work on my previous developer edition laptop). As I said, HDMI works but with lower refresh rate.
* I am using prebundled ubuntu's 14.04.4, patched with the latest upgrades and latest BIOS update 1.3.3
I am using the Color-3D CAC-1504 USB-C to HDMI 2.0 adapter, and it works perfectly. It does not have DisplayPort, but it should work up to 4K@60Hz. Not sure if that helps...
Possibly a driver issue. I've been experimenting with Fedora 23 and it didn't really work very well until the 4.4-kernel (in fact, I suspect some of the minor updates in that series is vitally important too, but with 4.4.6 from Fedora it seems to work). I suppose they could have missed backporting some things to the Dell bundled Ubuntu, or haven't done it yet?
Note though that my machine is the XPS 15 9550. Testing with BUTEFO SuperSpeed USB-C to DisplayPort 4K adapter.
If you have an external disk you could try installing Ubuntu 16.04 or Fedora 23 (or even the Fedora 24 Alpha) on that, and boot from it to see if that works better, if you want to test before messing with the internal installation. (Don't forget to install all the distribution updates before testing.)
Thank you for your detailed answer, I'll try with the latest 16.04 build.
It would be great that @barton or the team could confirm if usbc->DisplayPort works on the pre-bundled Ubuntu 14.04.
May I please second that on the vga output?
I know vga seems outdated, but some projectors still rely on that.
Thanks for any information.
just reporting that I am experiencing the same problem on my XPS13 with Ubuntu 18.04.2 LTS.That is usb-c to Display-Port stopped working with no apparent cause. Did anyone already find a solution?