Comment # 6 on bug 1023783 from David Pati�o

(In reply to Max Staudt from comment #3)
> (In reply to Fabian Vogt from comment #2)
> > That way you disabled the vc4 kernel driver which forces the system to use
> > efifb instead, which is known to be broken.
> > You only need to disable hw acceleration by writing this into
> > /etc/X11/xorg.conf.d/20-kms.conf:
> > 
> > Section "Device"
> >     Identifier "kms gfx"
> >     Driver "modesetting"
> >     Option "AccelMethod" "none"
> > EndSection
> 
> After doing the above, please also delete /etc/X11/xorg.conf.d/20-fbdev.conf
> in order to not confuse the system with contradictory settings.


OMG! That seems to fix the problem when vc4 is enabled. Thank you very much.

On the other hand, I dont have /etc/X11/xorg.conf.d/20-fbdev.conf file.

I've downloaded my current image file around November'16, but the last image
I've tested is from January'17.

Many thanks, also for the explanation.