In short, the hot key Fn + F9 (or F8, whatever) to toggle enabling touch pad (track pad) does not always work due to Linux’s poor driver support (It’s the manufacturer’s fault, not Canonical’s).

I kinda came up with the following workaround.

The basic

Basically, an unsupported touch pad will be emulated as a psmouse device. The following command will disable it.

sudo modprobe -r psmouse

To enable it, run

sudo modprobe psmouse

To check if the touch pad is enabled or not, check if psmouse is listed in the result of the following command

lsmod

A little more advance

So I decided to write a bash script to toggle enabling touch pad, instead of typing different commands for that

#!/bin/bash
if [ "`lsmod | grep -o psmouse`" ];
then
    sudo modprobe -r psmouse;
else
    sudo modprobe psmouse;
fi

I put the script in ~/Programs/scripts/toggle-trackpad.sh

Now, all I have to do is to run that script whenever I want to do the toggle. That doesn’t really make my life easier. Then I came up with these ideas.

1. Using alias

   So, I put this in the alias section of my ~/.bashrc file (I don’t use a separate ~/.bash_aliases file, since it’s not really necessary)

    alias toggle-tp="if [ \"\`lsmod | grep -o psmouse\`\" ]; then sudo modprobe -r psmouse; else sudo modprobe psmouse; fi"
   

   Ok, that looks nicer. Hummm, but then I will have to open a terminal every time I want to toggle the touch pad. Not catastrophically annoying, but I want things better.

2. Using Alt + F2 and gksudo

   Firstly, I install gksu. modprobe requires sudo access to work. Without a shell, gksudo is required.

    sudo apt-get install gksu -y
   

   Then, I change the alias to

    alias toggle-tp="if [ \"\`lsmod | grep -o psmouse\`\" ]; then gksudo 'modprobe -r psmouse'; else gksudo 'modprobe psmouse'; fi"
   

   After re-login, I can just press Alt + F2, then type toggle-cp to toggle. That’s a bit better, but still, I just want a hot key.

3. Custom shortcut

   So finally, I decide to edit the script in to use gksudo

    #!/bin/bash
    if [ "`lsmod | grep -o psmouse`" ];
    then
        gksudo 'modprobe -r psmouse';
    else
        gksudo 'modprobe psmouse';
    fi
   

   Then config a new keyboard shortcut (I’m using Ctrl + Super + T)

    Name: Toggle Keyboard
    Command: /path/to/toggle-trackpad.sh
   

Result

Now I can use a hot key to toggle enabling the touch pad. It’s still a little annoying that every time I want to toggle the touch pad, I would have to enter my password. Fortunately, I don’t have to do that too often. I use a mouse. It’s also a little disappointing that I can’t override the default Fn + F9 on my machine, but that’s minor. I’m happy enough.