[Nouveau] Text sometimes missing on NV18 based laptop

[Clemens Eisserer]

Hi again,

> On my NV18 based laptop I experience artifacts related to text
> (however, 2D performance is really great these days):
> - With grayscale AA text is sometimes missing, often visible on the XFCE desktop
> - With subpixel (rgb) AA, even non-text related occur (icons are
> misrendered, ...)
>
> I've reported the issues here:
> https://bugs.freedesktop.org/show_bug.cgi?id=81283

I know NV1x isn't anything spectacular or exciting to work on, however
on that notebook I don't have any choice.
Therefore I would be really grateful for advice how to narrow the
issues reported down.

Even finding a way to selectively turn off the accel-paths which cause
the issue would be a big win, as with noaccel the system is barely
useable.

Thank you in advance, Clemens