Bug#800938: Bug#799948: Plasma desktop is unable to start (black screen - panic)

[Vladimir Stavrinov]

On Mon, Oct 19, 2015 at 10:11:45PM +0100, Luca Boccassi wrote:

> Maybe there's some context I'm missing. Forgive me for asking, but are
> you sure this is due to the Nvidia driver packages or glx-alternatives?

Absolutely. This is Nvidia driver problem. Few days ago I conducted
specific experiment. After upgrading to latest version of all nvidia
and glx packages, I've downgraded only kernel module and after
reloading module the glx got working. But after rebooting system the
problem returned again. So not only kernel module is problem, but it
is main.

> Andreas, you use KDE if I'm not mistaken. Are you seeing any issues? Do

How many times again: this is not problem of KDE, plasma, kodi or any
other software using glx. This is problem of glx in nvidia driver. 

I am using xlock from very old package xlockmore-gl not included in
any of today's debian distributions. But it has two options
"-modelist allgl" and "-modelist all-allgl". First is for include glx
modes, second - to exclude ones. This is very good for testing glx,
because it explicitly points to glx as the source of problem when it
works with second option and doesn't work with the first one.

So it is certainly clear, that the source of our problems is glx
feature of nvdia driver. But the fact that You can't reproduce the
problem (if You can't, because You never mentioned this) may mean,
that problem is somehow hardware specific. In this case there are no
way to debug it as to ask us to do for You some experiments of Your
choice.

Here is my hardware:

lspci | grep -i nvidia
01:00.0 VGA compatible controller: NVIDIA Corporation GK208 [GeForce GT 635] (rev a1)
01:00.1 Audio device: NVIDIA Corporation GK208 HDMI/DP Audio Controller (rev a1)

If this guess is not true and the problem is not hardware specific, then You
should try number of different software using glx to reproduce the
problem.

And finally it is possible, that at some point of investigation You
will understand necessity to escalate the problem to upstream.

###  Vladimir Stavrinov  ###