Manually specifying a monitor as non-Apple display?

[qvacua]

I have the following setting: MacBook Pro (M1 Pro) with macOS 12.1 + LG UltraFine 4K 21.5" + Dell U2719D. Sometimes–I could not find out when exactly this happens–macOS recognizes the Dell monitor as brightness-controllable monitor, i.e. the Display settings or the Control Center shows a brightness slider for it. When I use the slider, the brightness of the LG monitor changes 😞.

MonitorControl thinks that the Dell monitor is an model/AppleDisplay since the system returns a value for the brightness (if I read the code correctly; DisplayManager.isAppleDisplay()). And it changes the brightness of the LG monitor when I use the slider for the Dell monitor (as expected).

Would it be an option to include an option to "force" a monitor to be a model/OtherDisplay? I've filed a bug at Apple, but I guess this won't be fixed...

[waydabber]

Hi @qvacua - I think you should add a Feature Request with a title "Force DDC control when macOS display as Apple display". It could be implemented quite easily.

[waydabber]

Or I can convert this discussion into an issue. :)

[waydabber]

#853

[qvacua]

Thanks!