[Nouveau] "enable dri3 support without glamor" causes gnome-shell regression on nv4x

[Hans de Goede]

Hi Maarten,

xf86-video-nouveau causes a garbled display when running
gnome-shell on nv4x (tested with nv43 and nv46) since this commit:

http://cgit.freedesktop.org/nouveau/xf86-video-nouveau/commit/?id=241e7289f25a342a457952b9b0e539c2f0b81d99

I've seen some discussion about issues caused by enabling dri,
but AFAIK no solution let.

I have time to help with debugging / fixing this, but I will
need some guidance where to start as I'm still learning
the ropes wrt nouveau.

Regards,

Hans