Ok, it seems as Intel has just 'forgotten' to make their newest drivers available. That's why they are not included in 16.04.
There is a German article on that available here: http://www.heise.de/newsticker/meldung/Linux-Intels-neue-Iris-Grafik- Treiber-Support-in-Sicht-3193993.html (translation: https://goo.gl/Cm18Kv). It mainly describes the (much bigger) issues with the Iris-550 GPU. However, they acknowledge that the missing driver patches might also affect users with HD 510 and HD 535 GPUs (so I guess also the HD 520 one). Let's hope the Ubuntu developers integrate the already available patch as soon as possible. Maybe there is a temporary work around? -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1559308 Title: Plugging HDMI screen in causes system hang To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1559308/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp