[Intel-gfx] [PATCH 3/3] drm/i915: Use intel_plane_obj_offset from more places

[Chris Wilson]

On Thu, May 28, 2015 at 02:24:40PM +0200, Daniel Vetter wrote:
> On Thu, May 28, 2015 at 09:58:30AM +0100, Tvrtko Ursulin wrote:
> > 
> > On 05/27/2015 10:15 PM, Chris Wilson wrote:
> > >On Wed, May 27, 2015 at 10:52:34AM +0100, Tvrtko Ursulin wrote:
> > >>From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> > >>
> > >>These are the display call sites so should use the proper helper.
> > >>
> > >>Also requires intel_plane_obj_offset to assume normal view when
> > >>plane pointer is not available.
> > >
> > >Eugh. If only the plane stored the offset, bonus marks for storing the
> > >vma cookie, then we would not have to keep recomputing the view and
> > >searching every single time...
> > 
> > Well, the patch even decreases the number of searches! :)
> > 
> > And we don't recompute when querying the offset - it just figures out what
> > type of vma it should look for. So I think it doesn't prevent any future
> > caching improvements. It actually makes it easier since it consolidates the
> > query.
> > 
> > I'll need this, or something like it, for some future work. So at the very
> > moment I am not too bothered if this goes in or not.
> 
> Yeah unfortunately we can't eliminate the view searches completely since
> the view depends upon fb + plane_state. So not perfectly aligned with our
> hw ... Otherwise I'd agree, caching the view in the fb would be neat.

Not in the fb, in the plane_state. We acquire the vma for the plane
during prepare and then we should be using that vma reference for the
lifetime of that atomic plane state.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre