Lenovo W520 touchpad disable w/o GUI

[tomliotta]

LM has a Mouse/Touchpad preference app in which the touchpad can be disabled/enabled. Also, there are a few command line methods to enable/disable the touchpad, but these are effective only for the current session and revert after a reboot. Those commands can be put into a startup script, but they obviously don't perform the actual same function as the GUI else they'd persist across boots.

Is there a method by way of command line of effecting the same result as the GUI? Or perhaps, exactly what does the GUI app do when the touchpad is disabled/enabled in order to make it stick across session?

The longer story:

I picked up a Lenovo ThinkPad W520 and installed LM 18.2. The widely known "mouse/touchpad button" problem started to appear during install and made the system practically unusable after install. Loads of research convinced me that (1) the problem has been known for years and (2) there is no known fix. However...

I bought the W520 with no HDD because only Windows was ever preinstalled, Windows merely added cost and problems, and I have numerous spare HDDs lying around. When it arrived, I plugged in a spare 160GB drive for testing, inserted a LM 18.2 USB and booted up. For a split second, I was surprised by a login screen asking for my password. I momentarily wondered how I'd messed up the USB, but quickly realized that the HDD had an older LM 17.1 on it, and that's what was showing up. (Whew.)

Okay, fine... start over. Set the BIOS to boot from USB (doh!) and I chose to install 18.2 next to 17.1. This semi-went well, with difficulty due to the mouse/touchpad problem; but the install was good. Next, I started looking into the problem.

Since booting to 17.1 let always everything work normally and the Internet comments I'd seen were referring to LM 18.x, I wondered if it was a difference between 17->18. So, I did a fresh full install of 17.3. Nope, didn't work. Tried 17.2, but no good. Tried 17.1, but still no good.

confused? It was working. Hmmm...

Why did it work originally but not now? The difference that came to mind was that the original 17.1 was installed on the HDD on a Lenovo T500. Perhaps that made a difference.

So, I moved the HDD to an older Lenovo T500, installed 17.3, disabled the touchpad (as I always do because I don't like them), tested it out, moved it to the W520, and it worked just as I wanted.

Apparently, by disabling the touchpad using the GUI, the trackpoint and its buttons all work correctly even on the W520. Unfortunately, the GUI controls are not accessible (won't select, won't change state) on the W520 when the touchpad is enabled; and 'Enabled' is the default state after install. Catch-22...

Hence... How to cause the same effect as the GUI without using the GUI? The temporary changes via xinput, etc., are somehow different.

[tomliotta]

With no replies, the next direction might be to track down the source for the GUI app. Does anybody know how to get closer to the source for it? Is there any point of contact for a developer?

A trivial app that performed no function except 'Disable touchpad' as the default action when {Enter} is pressed could be ideal. Stripping everything else out of the existing app would get it very close. A few more tweaks after that should get it there. I'd just need the starting point.