[Intel-gfx] [PATCH] drm/i915: flush system agent TLBs on SNB so we can WC map the PTEs

[Jesse Barnes]

On Thu, 11 Oct 2012 20:29:47 -0300
Paulo Zanoni <przanoni at gmail.com> wrote:

> Hi
> 
> 2012/10/11 Jesse Barnes <jbarnes at virtuousgeek.org>:
> > I've only lightly tested this so far, but the corruption seems to be
> > gone if I write the GFX_FLSH_CNTL reg after binding an object.  This
> > register should control the TLB for the system agent, which is what CPU
> > mapped objects will go through.
> >
> > Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
> 
> I'm not sure if this is the patch you asked me to test on IRC, but,
> well this is the patch I tested :)
> 
> I tested it on HSW on top of dinq + some other patches. Booted the
> machine, ran mostly xfterm4 under Xfce, but I also ran firefox,
> gnome-shell and restarted X a few times. No GPU hangs so far. I'm
> testing this for about 3-4 hours.
> 
> I do have to say that I could not find this register on the HSW
> documentation, but I also did no see any "Unclaimed write" messages
> containing the 101008 address... I'm a little confused.
> 
> And the interesting thing: intel_gpu_tools is useless now. I keep
> getting "Couldn't map MMIO region: Resource temporarily unavailable".
> Do you see this too?

No I haven't seen that, I ran some tests today with the tip of the tree
too...  Dunno why the resource files would return EBUSY?  Maybe because
a driver is bound?

-- 
Jesse Barnes, Intel Open Source Technology Center