Comment # 7 on bug 1005323 from Stefan Dirsch

(In reply to Ludwig Nussel from comment #5)
> (In reply to Stefan Dirsch from comment #0)
> > Please add this to Leap 42.2 release notes. Thanks!
> > 
> > --
> > Nouveau 3D/DRI driver disabled by default
> > 
> > With Leap 42.2 we are forced to consider the nouveau DRI/3D driver as
> > experimental.
> 
> Why now and not in 42.1? Are there bug reports that back this?

Sure. Multithreaded KDE apps no longer start with nouveau DRI driver. KDE on
42.1 did not use this feature yet.

> > Customers not interested in installing the proprietary NVIDIA driver for fast
> > 2D/3D support can install this package, though at their own
> > risk. Unfortunately the nouveau DRI driver does not work together with
> > current multithreaded KDE apps.
> 
> What does that mean? Crash, lockup, display glitches? How bad? NVidia cards
> are
> pretty wide spread and KDE is the default desktop. We need a bit more than
> release notes documentation if we know that this combination is broken.

KDE apps are crashing immediately.

> > We have prepared patches for Mesa to mitigate this issue, but have not
> > included them as per the author's intent: Using them may deadlock the system.
> > Experienced users running KDE and willing to use these patches can rebuild
> > the Mesa package after setting use_broken_nouveau_locking_patches %define in
> > specfile to 1.
> 
> Remove that paragraph. Recompiling Mesa is out of scope for the target
> audience.

Fair enough. We tried to address the issue with these locking patches, which
improved the situation a lot. Later we figured out that upstream does not want
to have these patches applied, since they believe they can easily deadlock the
userspace. So we had the idea to make everybody happy. Normal cutomer, nouveau
upstream and experienced users. Oh well ...