Re: [PATCH 4/5] drm/i915: Always flush tiling changes before accessing through the GTT

Chris Wilson
2012-04-14T21:59:40Z

On Sat, 14 Apr 2012 23:54:52 +0200, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Sat, Apr 14, 2012 at 09:55:50AM +0100, Chris Wilson wrote:
> > As we defer updating the fence register from set-tiling to the point of
> > use, we need to declare every access through the GTT as either fenced or
> > unfenced.
> >
> > This patches fixes up a couple of freshly introduced GTT accesses which
> > missed the fence flush.
> >
> > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>
> Actually no, this set_to_gtt is actually just a flush+wait_rendering
> because the shmem pwrite/pread afters does clever in-line clflushing.
> Abuse of interfaces, I know ...

Probably best to leave a note, so the next time I do a grep looking for
use of set-to-gtt without a following fence declaration, I don't submit
another patch. :-)
-Chris

--
Chris Wilson, Intel Open Source Technology Centre