nouveau driver & installation hang with G72/NV46

[Riccardo Mottola <riccardo.mottola%libero.it@localhost>]

Hi all,

as written some times, I have issues with nVidia (pesky cards!) - NetBSD
crashes as soon as initializes the framebuffer.
I asked for help several times... up to 9.1...

I just upgraded to 9.2 and had a bad experience: the bood kernel of the
CD fails and hangs!

I think this is really a bad experience. Since I debugged this a lot, I
quickly knew "boot netbsd -c" and "disable nouveau" to get the classic
text menus.

A very nice thing would be of course to have this issue fixed for "my"
G72 nVidia card [*]; but more broadly, this could happen for other cards.

I see three solutions
1) disable drm framebuffers in install kernels totally (OpenBSD does
this I think)
2) have a "whitelist" approach, what works, enabled, else... blocked. At
every confirmed card and/or fixed bug, add it to the list
3) have a "blacklist" approach... at every bug, block one, if bug
solved, remove it

What do you think? We should not scare users away with a crashing boot.

I found this related bug (another card than mine):
http://gnats.netbsd.org/cgi-bin/query-pr-single.pl?number=53492

If someone wants to hack, I can as I did in the past share logs, try
thing, disable stuff in kernel... debugging is the fun part - but I
propose also a broader solution for newcomers.

Riccardo

[*] The chip should be supported - in nouveau speak it is a NV46
https://linux.die.net/man/4/nouveau
https://nouveau.freedesktop.org/FeatureMatrix.html