16.04 Blank screen with AMD 460 graphics and gnome 3 (resolved with patch)

Question

I have an MSI Radeon RX460 graphics card, and have installed the latest (as of today) amdgpu-pro-driver, amdgpu-pro_16.30.3-315407.tar.xz. So far so good, good login screen at full 4k resolution. However, when I log in to a gnome 3 session, I get blank screens with a few lines of noise along the bottom of one monitor. There are windows there as the mouse cursor (which is displayed) changes as it's moved around. 2 monitors in use, 4K secondary, 2560x1440 primary.

Unity works fine, as does gnome flashback (both metacity and compiz), but not gnome, gnome classic nor cinnamon. However, my preferred desktop is gnome 3, and I'd like it to work.

uname -a says:

Linux chaos2 4.4.0-38-generic #57-Ubuntu SMP Tue Sep 6 15:42:33 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

lspci | grep -i VGA says:

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Device 67ef (rev cf)

lsmod|grep amdgpu says:

amdgpu               1961984  3
ttm                    94208  1 amdgpu
i2c_algo_bit           16384  2 i915,amdgpu
drm_kms_helper        147456  2 i915,amdgpu
drm                   364544  7 ttm,i915,drm_kms_helper,amdgpu

Can anyone suggest any way to fix this?

Thanks

Answer 1

Following the suggestion from GrannySez, I applied the patch using the method at phoronix.com/forums/forum/linux-graphics-x-org-drivers/… (a couple of posts down), and now have gnome 3 working. The package build process does fail, but manually installing the library works. The compiled library is much larger than the original, most likely because it is unstripped, but it works fine anyhow. If you apply the fix manually in this way be sure to put a hold on the cogl package, as suggested in the link.