I can confirm that I have this exact same issue with and AMD APU A10-8700P in an Acer E5-552G-T324 with the two graphics cards (the second being a Topaz XT [Radeon R7 M260/M265 / M340/M360 / M440/M445]).
When i take out nomodeset in the grub config and run sudo update-grub and then reboot my screen gets spammed multiple times with "AMD-Vi: Completion-Wait loop timed out". As Paul Sonnenschein reported nomodeset kills my 3D rendering and I would very much like to be able to have that. Also this machine mostly works good under Ubuntu Mate 16.04.2 except my screen flickers when switching to the screensaver and on boot up. Please let me know if I should upload further information in relation to this as I am new at reporting bugs. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-amdgpu in Ubuntu. https://bugs.launchpad.net/bugs/1683184 Title: GPU problems on HP 15-ba009ng To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-amdgpu/+bug/1683184/+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