Multihead - DVI numbers on which Xrandr acts are messed up at each reboot/relogin ... concurrent bindings?
Hello, Context : I have a fresh install of Xubuntu 20.04LTS just because historically I tended to have a lot more issues with Ubuntu for setting multiple monitors in the multiple locations I have to move my laptop.
The laptop has an intel iGPU and an nvidia 1050 dGPU. My Xubuntu uses the proprietary nvidia-440 driver, even though I suspect in fact the dGPU to never be used, since the monitors are not connected through neither :
DP-1-1 "native ports" (physically there is only one HDMI output plug on the laptop). It doesn't bother me, since most of my work is office-like and I don't play games. I did have issues when dockerized graphics applications required the dGPU to work but it's a rare case, let's forget it.
I used the command
arandr to generate me an
xrandr command line stored in
/home/me/.screenlayout/bashscript.sh, that's how I gave you these previous port names.
My issue is that actually all my 4 external monitors are connected to the laptop via 4 dedicated external, displaylink labeled, videocards. Each of these 4 devices are linked to the monitors via an HDMI-HDMI cable. Then the 4 devices go to a 3.0 7-USB hub, itself plugged to the laptop through a USB3.0 port.
The setup is like this, 2 landscape on the left of 2 portraits :
land2 , portr3, portr4
They are permanently plugged to the hub, let's number the physical location on the hub accordingly to the number associated to the displays.
The first time I ran
arandr, it associated to these ports, the following names (within the xrandr command) on its GUI :
DVI-I-4-3, DVI-I-3-2, DVI-I-2-1
However, when I reboot/wake up/log back in, these associations change randomly,
e.g: the OS (or idk what process) binds the USBhub port number1 to the name DVI-I-3-2, instead of its initial association to the port DVI-I-5-4.
Would it exist a way to get rid of this mess ?
- give a MAC address to the
--outputoption of the
- what part of the https://github.com/freedesktop/xorg-xrandr/blob/master/xrandr.c code does this association ?
- what is the "XID" mentionned here https://www.x.org/releases/X11R7.5/doc/man/man1/xrandr.1.html ?