Making a Logitech MX Master 3 Thumbwheel Work Under Linux

I have a Logitech MX Master 3 mouse which I absolutely love, it’s easily the best mouse I’ve owned (and I’ve owned a few) but as with many things Logitech it isn’t super well supported out of the box under Linux (Debian 12 in my case). For whatever reason Logitech pretty much acts like Linux doesn’t exist which isn’t great but their software is universally terrible so maybe it’s not such a bad thing. Fortunately some kind people developed Solaar which is a utility for managing and configuring Logitech devices. The only problem with Solaar is that it’s not terribly approachable for the average user.

At the heart of Solaar is its rule system. Once you’ve connected your devices, which seems to work really well, you need to set up rules for the various buttons and wheels it provides. Rules are made up of a number of conditions followed by actions that happen when the conditions are met. On the surface this sounds simple enough but there are a bewildering range of conditions and actions that can be selected.

In my case I wanted the thumbwheel on the mouse to control the volume, as I thumb up I want the volume to rise. After a fair bit of trial and error I settled on the rules shown below but read the description below.

Before you create rules for the thumbwheel you need to turn on “Thumb Wheel Diversion” on the main Solaar page. I believe the thumbwheel is supposed to scroll sideways by default but I don’t remember it ever doing that, the diversion setting allows it to be mapped to do something else.

I created a rule with two nearly identical sub-rules. The active condition is not strictly necessary and the rules work without it, I think it limits this rule to just the specified device, which is what I want. “Test” is a special condition for gestures. Reading what I could find on configuration I think Logitech reports thumbwheel input as a gesture which is currently not well supported, hence it lives under “Test”. Give this condition a positive numerical parameter such as 15. Higher numbers reduce sensitivity, if you leave it blank it’ll be far too sensitive. The action is “Key press” which causes the device to mimic a key press. If you are using X11 then you can probably copy what I’ve set it to which is “XF86_AudioRaiseVolume” or “XF86_AudioLowerVolume”, I don’t think this will work under Wayland at the moment. The