On Thu, Oct 11, 2012 at 12:43:42PM -0700, Jesse Barnes wrote:
> On Tue, 9 Oct 2012 19:24:38 +0100
> Chris Wilson <chris at chris-wilson.co.uk> wrote:
>
> > Now that we seem to have brought order to the GTT barriers, the last one
> > to review is the terminal barrier before we unbind the buffer from the
> > GTT. This needs to only be performed if the buffer still resides in the
> > GTT domain, and so we can skip some needless barriers otherwise.
> >
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > ---
> > drivers/gpu/drm/i915/i915_gem.c | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> > index 3c4577b..ed8d21a 100644
> > --- a/drivers/gpu/drm/i915/i915_gem.c
> > +++ b/drivers/gpu/drm/i915/i915_gem.c
> > @@ -2526,15 +2526,15 @@ static void i915_gem_object_finish_gtt(struct drm_i915_gem_object *obj)
> > {
> > u32 old_write_domain, old_read_domains;
> >
> > - /* Act a barrier for all accesses through the GTT */
> > - mb();
> > -
> > /* Force a pagefault for domain tracking on next user access */
> > i915_gem_release_mmap(obj);
> >
> > if ((obj->base.read_domains & I915_GEM_DOMAIN_GTT) == 0)
> > return;
> >
> > + /* Wait for any direct GTT access to complete */
> > + mb();
> > +
> > old_read_domains = obj->base.read_domains;
> > old_write_domain = obj->base.write_domain;
> >
>
> Yeah this looks like a better place to put it. You're trying to
> serialize this against a subsequent fence or map operation?
>
> Reviewed-by: Jesse Barnes <jbarnes at virtuousgeek.org>
Patches 1-2 queued for next, thanks.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
