Created attachment 241161 [details] dmesg after the error occured, dmesg after a similiar error occured browing a WebGL website, dpkl -l listing When viewing the satellite view in Google Maps with Google Chrome or Firefox the screen will become unresponsive and then go black. This occurs on other websites too but this is the most reproducible. Occasionally the screen returns and control is given back to the user, but often only the mouse works and desktop elements will not move around the screen when clicked and dragged. I have a Radeon 390x graphics card, a MSI Z97 Gaming 5 Motherboard and am running Kubuntu 16.04.1 LTS. This is a dual boot device with Windows 10 and have not seen any hardware issues in the Event Viewer. I filed this log here as the file that appeared in the dmesg log is part of the linux project "/build/linux-R0TiM8/linux-4.4.0/drivers/gpu/drm/radeon/radeon_object.c".
Can you try a newer kernel, ideally 4.8.y? I seem to remember running into this before, but no longer with current kernels. Unfortunately, I don't remember specifically how this was fixed.
This is resolved with upgrading to Ubuntu 16.10 (uses kernel 4.8), will follow a backport request with Ubuntu. If anyone knows the commit that resolves this issue please post.