[Nouveau] [PATCH] nouveau: nv46: Change mc subdev oclass from nv44 to nv4c

[Hans de Goede]

Hi,

On 27-07-15 17:52, Hans de Goede wrote:

> Slightly offtopic:
>
> I decided to be bold and try gnome-shell on the nv46 with msi disabled,
> which sofar was a guaranteed way to freeze the system, and it now works
> somewhat (latest kernel, ddx and mesa). I see something which shows
> horizontal lines which are small parts from my desktop background, and
> things change significantly when I switch to the overview mode.
>
> But other then that the display is completely wrong, it looks a bit
> like a framebuffer pitch problem, but then different. I think it
> is likely some tiling problem or some such.
>
> Note that metacity + glxgears works, this only shows with
> gnome-shell, any hints where to start looking wrt debugging this?
>
> Or should I first try to run piglet and see if some tests there
> point out the culprit?

I've been working on this today, I decided to first make sure
that the latest ddx + mesa did not have a regression on nv4x in
general, so I plugged in my nv43 card which used to run gnome-shell
fine and that shows the same problem.

Some debugging with that card shows that things break with this
ddx commit:

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

"enable dri3 support without glamor"

Using an older ddx + latest mesa master gnome-shell runs fine
on my nv43 card.

And adding my patch to disable msi interrupts on nv46 makes
gnome-shell run fine on my nv46 card too :)

So unless someone has a good idea to fix msi interrupts on
nv46, I suggest we merge my patch to disable them
(with a Cc: stable at vger.kernel.org), which should fix most
problems nv46 users have been seeing.

Regards,

Hans