I have a Dell Latitude E6410 laptop and it has one of those stick pointing devices built into the keyboard. They are just a little joystick that you can use to move the mouse except it is just a tiny little thing that fits between keys and is actually quite hard to use.
Anyway this week the stick thing started pushing the mouse to the top right hand corner all of the time. So I have looked up how to disable it from being in operation, since it was doing this with everything, even in the BIOS or the Linux installer.
So the command to use for (L)ubuntu is xinput so the first thing is to use its list parameter to get a list of devices. Each device will have an id number next to it, in this case 18.
Then the next thing is simply type in xinput disable 18 and that disables the device. Which means using the touchpad and an external USB mouse just got a whole lot easier. I’m not sure there is any hardware way like a key sequence you could press that would achieve this, so this was a great outcome, as I doubt there was anything else I could have done, although I was able to use the stick to move the mouse around. Without being able to resolve that the laptop would have been nearly unusable, which would be a concern as it is otherwise in extremely good condition.