Comment 71 for bug 1432194

Torsten. I also tried updating the kernel to 3.19 (on 14.04) first rather than installing 15.04. But once I updated and rebooted my wifi stopped working (the driver was not detected). Afterwards I did a fresh install of 15.04 and it has been over a week and I have no font issues..

I think you can first try using a live usb with 15.04 and use it for a while and see if you get any issues.