Where are framebuffers/visuals created?

[Greg V]

On Wed, Sep 26, 2018 at 4:32 PM, Bengt Ahlgren <bengt.ahlgren at ri.se> 
wrote:
> I'd like to try to debug and find the cause of this issue with Kwin, 
> but
> I don't know where in the graphics stack to start digging:
> 
> https://mail.kde.org/pipermail/kde-freebsd/2018-April/027704.html
> 
> In short, after an update of Mesa, Kwin complained about not finding 
> the
> appropriate framebuffer, and refused doing compositing with opengl.
> 
> So, my question is: where in the graphics stack are the
> framebuffers/visuals created?

Looks like a somewhat common issue with KWin, people have had it with

- Xinerama enabled on Nvidia: 
https://bbs.archlinux.org/viewtopic.php?id=123715
- Dual GPU laptops: https://bugs.kde.org/show_bug.cgi?id=323134

And this 32-bit requirement was dropped in KWin: 
https://git.reviewboard.kde.org/r/126262/
But that fix is probably only in Plasma5, not KDE4. (Time to drop KDE4! 
;))

Have you tried modesetting DDX (w/ glamor acceleration) instead of the 
(terrible) intel DDX?
Just deleting the intel driver should accomplish that, but just in 
case, manual xorg.conf config looks like:

Section "Device"
    Identifier  "GPU"
    Driver      "modesetting"
    Option      "AccelMethod"    "glamor"
EndSection