Bug#897631: Kernel update breaks GDM

[silvio.sabo@gmail.com]

Package: linux-image-4.9.0-6-amd64

The update for package linux-image-4.9.0-6-amd64 from 4.9.82-1+deb9u3
to the newest 4.9.88-1 breaks the autostart of GDM. This was on a fresh
install of Debian 9 (stable).

When I did the update after installing I couldn't login with GDM after
reboot, the boot would freeze. And I know that the NVIDIA drivers
(version 375.82-1~deb9u1) weren't loaded because the fan on my graphics
card are ramped up when the NVIDIA driver is not loaded (so when the
driver loads the fan will go silent).

I actually reinstalled the system a couple of times and the error would
occur every single time. Only installing the NVIDIA drivers after
install and not updating works just fine so it's not the NVIDIA drivers
that are erroneous. I found the error by installing updates one by one.
And after updating the kernel the error would appear.

Anyway the system refused to load GDM and the only way I could log in
was by switching to another TTY and log in from the command line.

However soon after logging in (usually by the time I had written a
couple of commands) GDM would start and I could then log in from the
GUI and from then on everything would work just fine. GDM would however
not start if I didn't log in from the command line, instead the system
would just hang indefinetly (I actually left it on for about 30 min
while going on lunch).

I ran 'systemctl status gdm3' right after logging in on TTY2 in and it
stated that it was indeed running but it wouldn't show the login screen
or load the NVIDIA drivers (since my graphics cards fans were going
full blast).

There also was no errors in any logs from what I could see. The gdm3
folder in /var/log was completely empty.

Rolling back to kernel version 4.9.82-1+deb9u3 resolved the problem.