Comment 60 for bug 541511

> --- Comment #58 from legolas558 <email address hidden> 2010-03-30 05:47:52 PST ---
> I'd be more than happy to mark it as "toasted" and go on, but then I wouldn't
> be able to use it with WindowsXP (never had a crash there) and neither with
> Xorg 1.6 (that works but because as you said the driver hits less frequently
> the cache).

The patch I intend to submit hopefully works better, too. By killing all
the gtt stress-testing hacks I've added you box is probably on par with
the other solutions.

> Has Intel ever released the WindowsXP driver sources? Yes, I know..just
> dreaming..

Likely won't help. The i8xx chipsets were designed without a kernel memory
manager in mind (Windows only gained that with Vista). So the XP driver
probably just implements a static gtt (that doesn't need any chipset
flushes) and copies textures back and forth. That works, but performance
will suck, especially with kernel-managed graphics memory allocation,
where spills happen rather often.

In other words, we're coxing these chipset into a framework they're not
designed for (but which is the only sane thing to do considering modern
graphics apis), trying to paper over any hw deficiencies with horrible
hacks like mine.

> Is there any other way that could explain the GTT<->CPU bug?

As long as there's no other report of the same problem, hw flakiness is
the only likely option. After all it only happens when hitting the gtt
really hard, something XP (and the old ums driver) are not likely to do.