Arch Linux

superjcvd

Member

Registered: 2019-09-16

Posts: 8

random problems with dual-screen and thunderbolt dock

Hello

I'm using Arch (and Manjaro) at work and at home for a few months now and I'm quite happy with it.
But I encounter an annoying problem with the dual screen management in Gnome.

I use a DELL 7480 Laptop with a Thunderbold dock station with 2 monitors.
I configured Gnome to use both external monitors in extended mode and shut down the laptop screen when docked.
-------------------------------------
[DELL-1]  [DELL-2]  [Laptop]
   ON       ON       OFF
-------------------------------------

But if I plug/unplug the USB-C port on the laptop the screen order get completely messed-up.
For example if I go to a meeting, when I come back and plug the laptop again on the dock the monitor 1 will be inverted with the monitor 2
DELL-1 will be inverted with DELL-2
Each time I replug the computer I have to cross fingers so that both monitors are displayed in the right order.

The command 'xrandr --listmonitors'
Will display different names for my 2 monitors each time I plug/unplug them
It's like each time I use the dock station the operating system thinks the monitors are new and creates a new device name for each.

I'm wondering if there is a way to fix the monitors order and device names in the system so that they don't get inverted each time I use the dock station (maybe some udev rules)
Any help or ideas are welcome It is quite boring to reconfigure the screens each time I dock my laptop

regards

Before undocking

 >>> xrandr --listmonitors                                           
Monitors: 2
 0: +XWAYLAND12 2560/530x1440/300+0+0  XWAYLAND12
 1: +XWAYLAND13 2560/530x1440/300+2560+0  XWAYLAND13

After docking again the laptop

~ >>> xrandr --listmonitors                                                                                                                                                         
Monitors: 2
 0: +XWAYLAND15 2560/530x1440/300+2560+0  XWAYLAND15
 1: +XWAYLAND16 2560/530x1440/300+0+0  XWAYLAND16

superjcvd

Member

Registered: 2019-09-16

Posts: 8

Re: random problems with dual-screen and thunderbolt dock

One more precision: I tried to use Xorg instead of Wayland but the problem stays the same

gnumdk

Member

Registered: 2009-10-15

Posts: 175

Re: random problems with dual-screen and thunderbolt dock

IMO, xrandr is listing Xwayland virtual screen, not your real Wayland screens.

Last edited by gnumdk (2019-09-17 06:31:08)