U2518D, Ubuntu 20.04, DP Daisy Chain problem

Question

I have just installed Ubuntu 20.04, but I can't get it to handle two monitor setup(both Dell U2518D with MST support). One monitor connected to DP works alright. When I connect the second monitor (Dell U2414H) to the first one through DisplayPort (daisy chain), the second monitor just mirrors the content of the first one. The second monitor not shown in Settings->Displays, only the first one. When I go into the setting on the first monitor using it's OSD and enable MST both screens go black and previously seen one display dissapear from ubuntu display settings). Side note: Worth mentioning that the entire setup works fine on Windows 10 and both screens are treated as separate screens. I have also tried Fedora 32 and Ubuntu 18.04 but same poop with all Linux distributions. For both Ubuntu 20.04 and Fedora 32 I have installed latest nvidia drivers, but that didn't help. Can anyone please help?

3headedmonkey · Answer

I have the exact same problem with two Dell U2415 monitors and a new XPS 13 9300 notebook running Ubuntu 20.04. Any help would be much appreciated.

jeyfox · Answer

exactly same problem for me, works no problem on winows but not in linux  GPU : intel ivybridge - driver : i915 screens : U2518D   any solution for linux?

BifurcatedFocus · Answer

Exact same problem. Two P2415Q monitors connected to a Radeon HD 6850, where miniDP to DP cable connects Radeon HD 6850,to first monitor (set to MST = Primary) and then DP to DP cable connects to second monitor (set to MST = Secondary).

On my dual-boot system, Windows 10 correctly detects two displays, and can show different content on each. Ubuntu 20.04 LTS only detects one display, and the displays are mirrored. My system has a Ryzen 5 3600, and a B550-based motherboard.

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