R9 270x with AMDGPU driver under Ubuntu 16.04 with new 4.9 kernel

Solution 1:

Be sure to have the latest kernel with amdgpu module and the latest AMD firmware (amdgpu-pro) in place, then try to set it for example in:

/etc/X11/xorg.conf.d/20-amdgpu.conf

like this:

Section "Device"
  Identifier "AMD"
  Driver "amdgpu"
EndSection

KMS must be enabled and amdgpu not being blacklisted. This should already do the trick. You could as well blacklist radeon module.

Not sure if your card is a "Southern Islands" or "Sea Islands" if this is the case you might need to compile a kernel on your own if:

CONFIG_DRM_AMDGPU_CIK=Y

or

CONFIG_DRM_AMDGPU_SI=Y

are not set in the kernel config. Which option to choose depends on your gfx card.

When changing gfx settings you're always in near danger that X doesn't start any more. It's a good idea having a 2nd computer for surfing documentation.

Folks I'm sorry I can't verify my answer because I've got no amd card. So please be kind.

This is a summary from:

• https://wiki.archlinux.org/index.php/AMDGPU
• The top of my head
• https://wiki.gentoo.org/wiki/AMDGPU