wrong monitor inputs detected

[rkitover]

I installed ddcutil 0.8.6 and screenstub, but screenstub detect does not show the right inputs:

rkitover@epyc ➤ sudo .cargo/bin/screenstub detect

Manufacturer: GSM
Model: LG Ultra HD
Serial: Unspecified
Input: DisplayPort-2 = 0x10
Input: HDMI-2 = 0x12
Input: HDMI-1 = 0x11
Input: DisplayPort-1 = 0x0f

I have HDMI1 through HDMI4, my windows VM is on HDMI4.

There is also a USB-C input.

And I only have 1 displayport input.

6 in total.

[arcnmx]

You can try and see what ddcutil capabilities says for Feature 60 / Input Source and see if it disagrees (might need -d 2 etc to change display number)?

In my experience from my LG 27UD58-B display, their implementation is kind of weird and buggy. It exposes those same 4 inputs, despite only having one DP and two HDMI inputs. Switching works properly only with certain ports, switching between two HDMI inputs resulted in a somewhat distorted image but between HDMI and DP works fine. You may need to swap around which physical inputs you use to get it to work.

You may also be able to poke around with trying other values to switch to and they may work for the other 2 ports despite not being listed in the monitor's capabilities string? Some values are assigned/reserved by vesa which the monitor may be using, or they could be using any arbitrary value from 0x13 to 0xff, or none at all.

Also that DP-2 value might be assigned to one of the missing ports, even. It just says DP-2 because that value is reserved to be DP-2 by the spec, and not because the monitor is necessarily saying that's what it is.