[Nouveau] Recommendation for cherry-pick between 3.12 and 4.2: 0a363e85cdaf

[Ilia Mirkin]

Hello,

I'd like to recommend backporting this commit:

commit 0a363e85cdafbceeee6a49b91c604d0d4d070dc7
Author: Hans de Goede <hdegoede at redhat.com>
Date:   Thu Jul 23 17:20:12 2015 +0200

    drm/nouveau/nv46: Change mc subdev oclass from nv44 to nv4c

This disables MSI by default on G72 (NV46) devices where it's
apparently a bit buggy. We have a later patch which turns MSI back on
with a quirk, but it isn't extremely necessary for these devices, and
disabling (or, rather, not enabling) MSI is a pretty safe thing to do.

The patch went upstream in 4.3-rc1, however I believe that there are
still a number of kernels between 3.12 (where MSI was first enabled by
default - commit a27e56996) and 4.2 (inclusive) which are still being
maintained. To those maintainers, please consider including this in
your trees.

Cheers,

  -ilia