[Intel-gfx] [PATCH 43/43] drm/i915: enable ppgtt

[Daniel Vetter]

On Wed, Dec 14, 2011 at 03:34:38PM +0000, Chris Wilson wrote:
> On Wed, 14 Dec 2011 13:57:40 +0100, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> > v2: Don't try to enable ppgtt on pre-snb.
> > 
> > Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> > Reviewed-by: Ben Widawsky <ben at bwidawsk.net>
> > ---
> > +void i915_gem_init_ppgtt(struct drm_device *dev)
> > +{
> > +	drm_i915_private_t *dev_priv = dev->dev_private;
> > +	uint32_t pd_offset;
> > +	struct intel_ring_buffer *ring;
> > +	int i;
> > +
> > +	if (!HAS_ALIASING_PPGTT(dev))
> > +		return;
> I still think it is safer to use
>   if (dev_priv->mm.aliasing_ppgtt == NULL)
>     return;
> here
> 
> And pretty please can I module parameter to enable/disable ppgtt on
> boot.

I hope we can really avoid this. Working ppgtt is more or less required by
a bunch of things, and will at least result in strange suprises with
real per-process address spaces. Disabling the use of ppgtt with the
current code can be easily done by resetting the NON_SECURE flag in the
MI_START_BB cmd (or disabling all of it in the HAS_ALIASING_PPGTT macro).
This should be good enough to hammer out any outstanding issues with this.
-Daniel
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48