Some Steam games have rendering issues with kernel update

[Andrey Krupa]

Updating kernel from linux-image-4.8.0-39-generic (4.8.0-39.42~16.04.1) to linux-image-4.8.0-41-generic (4.8.0-41.44~16.04.1) breaks OpenGL rendering/textures with radeon driver. Some textures are getting corrupted or zeroed/transparent.

1)
Description: Ubuntu 16.04.2 LTS
Release: 16.04

2)
linux-image-4.8.0-39-generic:
  Installed: 4.8.0-39.42~16.04.1
  Candidate: 4.8.0-39.42~16.04.1
  Version table:
 *** 4.8.0-39.42~16.04.1 500
        500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
        500 http://us.archive.ubuntu.com/ubuntu xenial-security/main amd64 Packages
        100 /var/lib/dpkg/status

Updated to:
linux-image-4.8.0-41-generic:
  Installed: (none) // removed this kernel as workaround
  Candidate: 4.8.0-41.44~16.04.1
  Version table:
     4.8.0-41.44~16.04.1 500
        500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
        500 http://us.archive.ubuntu.com/ubuntu xenial-security/main amd64 Packages
        100 /var/lib/dpkg/status

3) Play Civilization VI on Ubuntu via Steam expect to see smooth rendering with clear textures. This was the case with 4.8.0-39 kernel.

4) With 4.8.0-41 kernel rendering does not work as expected. Some corrupt/zeroed textures appear.

After installing new package version and reboot everything works until machine is power cycled. After machine is power cycled at lest once issue reproduce permanently. Reverting kernel with power cycle fixes issue.

* Report is not very specific, however, there is only one change in log related to this package upgrade. This might reduce scope of the search:
http://changelogs.ubuntu.com/changelogs/pool/main/l/linux-hwe/linux-hwe_4.8.0-41.44~16.04.1/changelog
linux-hwe (4.8.0-41.44~16.04.1) xenial; urgency=low

  * CVE-2017-2636
    - tty: n_hdlc: get rid of racy n_hdlc.tbuf

 -- Stefan Bader <email address hidden> Fri, 03 Mar 2017 12:23:03 +0100

[Andrey Krupa (kelqualyn)]

Some comment on why bug is marked as invalid:
This appeared to be "hardware" issue. Ubuntu/Steam runs as guest inside KVM. AMD Tahiti GPU used via vfio pci pass-through as secondary GPU with open-source radeon driver. Standard KVM VGA video adapter used as primary.
EFI is not used in guest. However, for some reason efifb framebuffer driver is getting initialized in this configuration. It allocates IO region that conflicts with radeon. Blacklisting efifb via grub command line "video=efifb:off" solved issue. Games run smooth with no corrupted textures.