Sometimes when I boot up my Toshiba Satellite L875D lap top running Ubuntu 12.04 LTS it does not detect my keyboard

Question

I have the follow issue. I am using Ubuntu 12.04 LTS on Toshiba Satellite L875D and sometimes when I boot up my machine it reaches the log in session where I am supposed to type my password but my keyboard does not work. So I am forced to restart my lap top using my mouse and then I face the same problem again right after the first restart at least once or twice until I am finally able to use my keyboard. The weirdest part is that when I restart my lap top to try to make my keyboard working Ubuntu doesn't boot up and it just stays on a black screen without doing anything so I have to use my turn off button to restart it, after that everything is fine. This trouble occurs from time to time but it is still very annoying I have googled my trouble issue trying to find similar topics or someone who has experienced the same problem but I couldn't. I will greatly appreciate any help from you guys. Thank you in Advance.

Answer 1

Confirmed (dual boot Ububntu 12.04 LTS on Toshiba Satellite C875D): on boot I lose my keyboard everytime if any combination of the following occurs after boot manager and before the password request screen loads:

press any key
touch the touchpad
click either button
have a USB pointer device plugged in.

Confirm the black screen of death after keyboard loss on attempted restart. Only hard power off restarts the machine.

Failure to resolve: Universal access sticky keys on or off
Failure to resolve: Enable or disable USB before or after boot
Failure to resolve: Enable or disable Bluetooth before or after boot
Failure to resolve: Updating kernal and drivers
Possibly related: Backlit keyboard does not light

Work around:

Do not touch any key nor button nor touchpad during boot.
Plug in USB pointer device AFTER login.
Hope that, when selecting Ubuntu at boot manager, the enter key did not bounce.
Always have Onboard running.

Answer 2

I had success appending a couple of parameters to my kernel boot string:

 i8042.reset i8042.nomux=1

Apparently, these laptops use an internal PS/2 port for the mouse and keyboard.