I installed a linux in my laptop but my brightness adjustment key stops working in linux. I am not sure if any driver needs to be installed or not.
I am using hp laptop and have installed ubuntu 14.04 linux.
No one can tell you how to make those key working again except when you tell the exact model of your device. If they don't work in linux then it means they need driver, look for the main website of your device to see if there are any linux compatible driver, if there wasn't any then you should look for the same problem people might have with same device in linux and then follow their solution. There would be probably some general drivers which make those keys work again.