After going on the #radeon channel on Freenode, we narrowed the problem
down to the switcheroo-control package. We started by hand making an
xorg.conf file and disabling gpu-manager, but still had issues. Looking
at the dmesg log, we saw that the discrete gpu is enabled at first, then
disabled sometime in the systemd start up. After trying to disable
various things, including switcheroo, from the kernel parameters and
having the problem still occur, we narrowed it down to being a service
that was writing to `/sys/kernel/debug/vgaswitcheroo/switch`. I looked
at my enabled services, and saw `switcheroo-control`, after disabling,
everything started working again.

Given that the package was integrated into gnome in late 2016 [0][1], it
lines up timewise with when I started having problems.

[0] 
https://askubuntu.com/questions/1034882/gnome-does-not-show-the-option-to-use-dedicated-graphics-card-on-right-click
[1] http://www.hadess.net/2016/10/dual-gpu-integration-in-gnome.html

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https://bugs.launchpad.net/bugs/1692437

Title:
  Monitors on second GPU not working after upgrade to zesty

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