2 Posts
1
6947
WD19TB Dock mirrors 2 external displays instead of extending on Linux
I'm running Ubuntu 19.10 on a Dell XPS 13 7390 2-in-1. I'm using the WD19TB dock to connect 2 external displays. Everything works except for the fact that my OS only detects 1 external display and mirrors the output to both external displays. I've updated the dock and laptop firmware the latest versions. I suspected a newer kernel might solve the issue but booting a 5.4 kernel didn't change anything.
Both displays are detected on Windows. Any ideas how this can be resolved?
ejar2020
2 Posts
1
January 7th, 2020 10:00
Hi again!
I just discovered that this issue goes away if I use the usb-c/tb3-port on the RIGHT side of the laptop instead of the left side. Really strange. But this works for me.
ejar2020
2 Posts
0
January 7th, 2020 09:00
Hi!
I have the exact same issue here.
Dell XPS 13 7390 2-in-1
2x Dell U2719D
Dell WD19TB
Kernel 5.4.0-050400-generic
Kubuntu 19.10
Bios 1.1.3
$ fwupdmgr get-topology
○
├─ WD19TB a455a3a21752e5d31c228f1f5b51761dad88a432
│ ├─ Thunderbolt controller in Dell dock b1865b9aefad99910e7297e696f388eb32e38401
│ ├─ RTS5487 in Dell dock acb404019656654d44f80922d94735e831d9bb40
│ ├─ Package level of Dell dock 1eca9eabb0c992c136e1deb1f89e3f70c465aa1c
│ ├─ VMM5331 in Dell dock 58931e8c9ef5eead9c007563814f96fcadb1b993
│ └─ RTS5413 in Dell dock ca36279eeac13463fd5d974c88794859294fbfb1
├─ XPS 13 7390 2-in-1 System Firmware fb5523b663445df99fe178d162a221546e1974af
├─ KBG40ZPZ1T02 NVMe TOSHIBA 1024GB e998c21a4056253aae7959d57a04935877aed779
Same problem if I daisy chain, use 1 HDMI + 1 DP or use 1 DP + 1 USB-C from the dock.
In windows 10 it detects both screens and connecting the screens directly to the laptop using daisy chaining also works fine.
user_810f27
2 Posts
0
January 7th, 2020 12:00
HAHAHA! I just tried plugging it in on the right side, and that does indeed make it work. That's hilarious! Thank you! Made my day
dell-mario l
34 Posts
0
April 29th, 2020 13:00
When you were trying to arrange the 2 external displays, were they all "horizontal"? I'm aware that various parts of the Ubuntu graphics stack (kernel, mesa, X) have had limitations where they couldn't have a texture larger than 8k in any direction. Setting up 3 monitors horizontally runs up against these limitations.
The reason I would suspect that it worked on the right port was that all the monitors were running in reduced resolutions relative to the left port (DP alt mode on the right and TBT mode on the left).
A few suggestions: