switched to kernel 4.7.2, seems to improve/solve the issue. definitely improvement of the lag when detecting a new display and returning to responsive state.
i7-6500u, intel® HD graphics 520, AMD FirePro™ W4190M, HP 15u G3 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to 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/linux/+bug/1559308/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs