Bug#875248: gnome 3.22: severe graphical glitches on Radeon HD 6670/7670 "Turks"

[Simon McVittie]

Control: retitle -1 gnome 3.22: severe graphical glitches on Radeon HD 6670/7670 "Turks"
Control: severity -1 important
Control: tags -1 + moreinfo
Control: reassign -1 gnome-shell 3.22.3-3

On Sat, 09 Sep 2017 at 18:49:34 -0300, Ramiro Lopes wrote:
> I'm experiencing severe graphical glitches on Gnome and Gdm3 that render
> the environment unusable. Borders of windows remain on screen, blinking, after
> moving, and typing on terminals is a mess, full of glitches that make it
> impossible to see the characters. Menus show highliting and blinking of
> several items when hovering over them. Chromium works fine though.

Are you still using the hardware for which you reported this bug?

I'm downgrading this to "important" severity, because while it makes
GNOME unusable *on your hardware*, it does not make GNOME unusable in
general. For now I'm reassigning to gnome-shell, but depending on other
information you provide, it might get reassigned again.

I suspect this is probably triggered by GNOME Shell being a compositor
that makes non-trivial use of GPU hardware, whereas Fluxbox treats your
GPU as though it was a simple 1990s graphics card. That makes GNOME
Shell much more vulnerable to kernel or driver bugs.

Your Radeon HD 6670/7670 seems to be a 2010 design that is meant to be
supported by the "radeon" driver family (not the "amdgpu" driver used
for newer AMD graphics hardware).

Do you get any interesting-looking messages in the system log,
particularly after starting gdm or GNOME? Please send the syslog
entries for a sample boot and login, censoring anything private with
XXX or similar.

Please could you also gather the package information from
"reportbug --template gnome-shell" and
"reportbug --template libgl1-mesa-dri", preferably running under X11,
and send that to this bug? That would tell us more about your hardware
and drivers. It would be particularly useful if you are able to run those
commands in a GNOME Shell session that exhibits this bug, because that
would give us the Xorg.*.log for that session.

> I'm using Fluxbox for now which works perfectly, showing no glitches,
> whatsoever.

Do other compositing environments or programs that make use of your
graphics hardware have the same problem? Here are some things to try:

* gnome-maps under Fluxbox (uses Clutter)
* openarena or a similar 3D game (uses OpenGL)
* gnome-session-flashback with compositing disabled
  (gsettings set org.gnome.metacity compositing-manager false)
* gnome-session-flashback with compositing enabled
  (gsettings set org.gnome.metacity compositing-manager true)
* GNOME in Wayland or X11 mode (do they behave the same or is one of
  them better?)
* MATE desktop environment (a fork of GNOME)

Test results for those would help to pin down where the problem is.

> I tried reverting all packages but that did not help.

Which packages did you try reverting?

Would you be able to test this on Debian testing/unstable (buster/sid)
on the same hardware? It's possible that this was fixed somewhere between
stretch and buster.

Thanks,
    smcv