Graphics problems after upgrading HWE Stack

[Björn Lisper]

I run Xubuntu 14.04 LTS on a HP EliteBook 840 G1. The update manager recently began prompting me for upgrading the HWE Stack, and so I did. Now I run the Ubuntu 16.04 Xenial HWE Stack and the kernel has been upgraded to 4.4.0-36-generic.

After the upgrade I experience some annoying problems:

1. Sometimes the screen goes blank, like if the screen-saver kicks in but randomly, it may take 30 seconds or half an hour between these events and regardless of if I do any activity or not. I will get the screen back if I move the mouse, just like for the screen-saver, but sometimes with some delay (from immediate to a few seconds).

2. If I close the lid so the computer hibernates, and when waking it up again, then, after login, the cursor will disappear from the screen. It is somehow still logically there, because I can see items being highlighted as as move the mouse, but the arrow is invisible. A reboot will fix it.

Björn