https://bugs.freedesktop.org/show_bug.cgi?id=98492
--- Comment #7 from Nicolai Hähnle nhaehnle@gmail.com --- What this setting does is disable support for the specified extension. The problem here is that the application uses the extension in a problematic way: by the way the extension is phrased, it should only work for allocations at a page-level granularity. X-Plane 10 tries to use it for a different granularity and doesn't check for error results (which it really must).
We could hack around the page-level granularity limitations in the same way that the closed-source driver does it, but I'm hesitant to do so because it can never be a complete fix: if two pinned buffers overlap on the same page, we simply cannot support that currently. So who knows what other potential application bugs we'd just be papering over.
As for a patch, we might add a driconf-based application-specific workaround for this.