>Could you please suggest any solution for the open-source driver overheat
issue?
I've struggled with an ATI GPU for months back when I had a laptop with one
of those horrible graphics cards. All Ati cards require proprietary firmware
for video acceleration to work. As of the linux kernel 3.11 they also require
the same blob just to display the correct native screen resolution.
I can give you a non-solution: install Debian and keep it as it is by default
(libre) and then add temporarily the non-free repo to install the package
firmware-linux-nonfree.
Then remove from sources.list the non-free repo. That way you'll have a libre
distro with only the non-free firmware for your GPU (which is better than
keeping Buguntu but still bad for your freedom..)
I can also give you a real solution: sell your laptop and with the money you
earn from it buy yourself a laptop with an Intel integrated GPU older than
skylake.
cheers
