Bug#998378: Half-solution

[Julien Puydt <julien.puydt@gmail.com>]

Hi,

I managed to get the second screen to work, by adding intel_iommu=off
to GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub/.

But it's pretty unstable: disconnect the cable, open a window, and the
gui system restarts -- the system doesn't crash completely, though.

I haven't been able to get much out of journalctl yet ; I will try to
get more information on the matter.

In the meantime, there's already something clear to improve the
situation: make the kernel detect intel_iommu should be disabled in
certain conditions.

Cheers,

J.Puydt