Ok, I applied this, even though I hate the timing.
I also suspect that that whole commit 61b365a50 ("drm/nouveau:
populate master subdev pointer only when fully constructed") is just
completely buggered and the wrong thing to do. It also caused another
nasty change (fdd239ac99a0 "drm/nouveau: fix
Since commit 61b365a50 (drm/nouveau: populate master subdev pointer only
when fully constructed), the nouveau_mxm(bios) call will return NULL,
since it's still being called from the constructor. Instead, pass the
mxm pointer via the unused data field.
See https://bugs.freedesktop.org/show_bug.cgi?
