I still have Ubuntu 11.04 installed on my laptop which is a Dell XPS 15 L502X and comes with Nvida Optimus Technology. Yeah, I know you must be thinking why I am still on Ubuntu 11.04 when it’s been quite some time since the release of 12.04. Well, the answer is mostly because of good ol’ Gnome 2! Anyways, for using Optimus cards on Linux, you got to have Bumblebee installed.
So, I had some updates pending and when I updated my system and rebooted; optirun wasn’t launching any applications. I submitted the issue on Bumblebee’s Github page, to which they replied instantly and solved the problem in no time! Kudos for that to the Bumblebee team :). The initial solution was to downgrade the nvidia-driver. Although, later they gave me a solution as to how to use the updated nvidia-driver but this situation brought me yet another lesson, sometimes you gotta downgrade! For tasks like these, Synaptic Package Manager is an excellent choice. Here’s, what you should do to downgrade a package:
Step 1) Open Synaptic Manager and locate the package you want to downgrade.
Step 2)In Synaptic Manager, go to Package –> Force Version and select the version that you want. Apply the changes. After applying the changes you will notice a “star” marked on the package.
Step 3) When you downgrade a package, Update Manager will give you an update to upgrade. So, you’ll be back to square one. To stop getting updates for this package, lock it. Select the package and go to Package -> Lock Version and you are done. When you lock any package it will be marked with a lock and will be highlighted with “red” color.
Remember, older version of a package may have some holes!!