External Display using USB-C to HDMI // Silicon Motion Graphics (SMI)

[georgedobreff]

IMPORTANT!

This guide is specific for USB-C to HDMI adapters that use Silicon Motion drivers.

If your adapter is using base DisplayLink just run sudo pacman -S displaylink, reboot and it should work. If it doesn't - join the Discord via the link at the bottom and @ me.

Adapters with DP alt mode (most of them are like that) will not work no matter what you do. DP Alt mode has not yet been reverse engineered (thanks Apple).

When browsing for an adapter you're looking for something like this in the description:
Compatibility: Driver installation is required. The UGA-HDMI-2S uses Silicon Motion (SMI) graphics software.

CHECK THE REFRESH RATE SUPPORT BEFORE YOU BUY AN ADAPTER!

Here's one I found on Amazon US that uses SMI Drivers

Another one for UK (the one I use)

You'll have an easier time if you search for M1 Air x2 HDMI adapters as that model has only 1 display supported via DP Alt mode so anything that has 2 ports will be DisplayLink or SMI.

Let's begin

SMI drivers are broken (surprise surprise) after the last Linux Kernel update. Don't worry I got you. Get the fixed one from here

Once you've downloaded this as a zip extract it.

• Open a terminal and navigate to that folder.
• yay -S evdi-dkms and go through the install.
• sudo ./install.sh
• Reboot when its done.

Now we need to configure the monitor(s).

• Obviously, make sure they're plugged in and powered on lol

• Option + Command + Space opens the Omarchy menu. Navigate to Setup then Monitors.

• Don't touch anything yet in that file yet. Open a terminal and execute hyprctl monitors

This will give you a list of your monitors. eDP-1 is your built-in display. You're looking for the other(s). More specifically for the monitor name. For example I have one called DVI-I-1 and another DVI-I-2.

• With the monitor(s) identified go back to the monitors.config you opened and add the following
  monitor= DVI-I-1, 1920x1080@60, auto, auto
• Replace DVI-I-1 with your monitor name.
• If you have another monitor add another line for it.

You should have something like the config in the image above.

I recommend you keep the resolution at 1080p and refresh rate at 60 as a start until you've confirmed it works then you can modify as you wish (or as much as your adapter supports).

If the monitor(s) does not turn on immediately then reboot and it should work fine.

HELP! It still doesn't work!

Answer these questions:

• Did you try to turn it off and on again?
• Is your adapter Display Link or Silicon Motion dependent ?
• Are you sure?
• Did you install evdi-dkms first ?
• Did you configure AND SAVE the monitors.conf properly ?
• Did you restart after that ?

If you answer "yes" to all of these and it's still not working - get in the Discord and bribe me to help you (I accept only quality memes as payment)

Everything working now ? PERFECT!

Say thanks: