Feature Request: Automatically Reset VMM7100-Based HDMI Adapters on Wake [Update: DONE]

[jitdor]

I’m using a VMM7100-based USB-C to HDMI adapter (Cable Matters) between my Mac Studio and a secondary display. To support 4K120 10-bit HDR output over HDMI, the adapter has been flashed with a modified firmware provided by the manufacturer that enables DisplayPort Alt Mode over HDMI.

However, there’s a recurring issue: whenever the Mac wakes from sleep, the secondary display fails to wake properly. It repeatedly powers on and off, with a black screen and no signal. The issue can be resolved by either rebooting the Mac Studio or physically reconnecting the USB-C cable.

Recently, I discovered that invoking the “Reset VMM7100 HDMI Adapter” function within BetterDisplay also successfully resolves the problem—no restart or cable replug required.

This brings me to a potential feature request:
Would it be possible to add an option for BetterDisplay to automatically trigger the reset command for VMM7100-based adapters on wake-from-sleep events?

This automation would greatly improve usability for setups like mine, eliminating the need for manual intervention every time the Mac wakes.

Thank you for the excellent work on BetterDisplay and for considering this request!

[waydabber]

Hi there - this feature is already implemented, should be available under Settings/Displays/Overview/Additional settings...

You can also assign a keyboard shortcut to it.

[jitdor]

Thanks for the quick reply!

Just to clarify — if you were referring to the “Reinitialize external displays with flexible scaling if needed” option, that unfortunately doesn’t resolve the issue in my case. I’ve also tried the “Reinitialize External Displays” action from the drop-down menu, but that didn’t work either.

The only action that consistently restores proper signal to the secondary display is the “Reset VMM7100 HDMI Adapter” action from the drop-down menu. However, it seems this specific reset action isn’t triggered by any of the items under Settings/Displays/Overview/Additional settings.

Thanks again for your support and for looking into this!

[waydabber]

Hi there,

no, there should be a separate option there Reset all VMM7100 devices before wake or unlock reinitialization for this display. But this is only visible when the Reinitialize on wake or unlock is enabled and there is a recognized VMM7100 device.

[jitdor]

Works perfectly now — thank you so much for the quick fix and support! Really appreciate it.