Interest in nvidia-driver debugging on 5-*

[Terry Lambert]

Evan Dower wrote:
> I am highly interested in getting nvidia-driver to work well for FBSD, and
> in particular my own computer. I do not have the expertise to hack on either
> it or the kernel (yet), but I am eager to provide debugging information.
> nvidia-driver frequently crashes my machine, so I expect that my input could
> be valuable. Is anybody interested in my assistance? Is anybody actively
> working on/with/around the nvidia-driver, or does the license make that
> infeasible?

As was pointed out the other day, nVidia use the %gs register
without saving and restoring it, in order to maintain their
internal thread state.  Now that FreeBSD also uses this
register, that causes crashes.

I believe the fix is as simple as saving and restoring %gs in
the nVidia driver, and/or not letting the nVidia use %gs at
all (segment registers generally belong to the OS, in any case,
and stealing a CPU register of any kind for exclusive use of a
driver is a pig trick).

-- Terry