Comment 9 for bug 1579374

As I reported here:

https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-amdgpu/+bug/1608042/comments/31

...my computer is exactly the same (Dell Inspiron 5448 laptop, BIOS A06, hybrid graphics Intel Broadwell - module i915 + AMD Topaz XT R7 M260/M265 - module amdgpu) and after installing 64-bit XUbuntu 16.04 "Xenial" I got the same problem, because of the kernel 4.4.

I got rid of the kernel-AMD GPU issues after doing some reverse commit and identifying that kernel 4.6-rc1 received a "good commit" that fixed the problem.

I'm currently running 4.6-rc7, but I can confirm that from 4.6-rc1 ahead the "NULL pointer dereference" bug's gone. From kernel 4.6-rc1 or newer I'm able to execute "DRI_PRIME=1 glxgears" without experiencing any issues.