I had one a long while back that was not set and I could not find a thing on it. I called the manufacturer. Their fix was for windows. However there is an app called regionset you can try. Some dvd players in Linux will ignore regions. There is also a flash update app for windows that will allow your drive to use multiple regions.
In Linux it may be illegal to watch encrypted dvd's that are sold commercially.
It may also be illegal to set regions other than your own.
If you or your friends from another country have some home movies or something you produced you may be able to use Linux legally to watch them, but I don't know.
You should consult your lawyer before inserting a dvd. Especially if you bought it from the store with your own money, as this may constitute some sort of contractual agreement. And have someone posted for the dvd police while the movie plays, just in case.