Re: [PATCH 14/15] drm/i915: Track frontbuffer invalidation/flushing

Chris Wilson
2014-06-17T08:10:25Z

On Tue, Jun 17, 2014 at 09:52:17AM +0200, Daniel Vetter wrote:
> On Tue, Jun 17, 2014 at 08:00:05AM +0100, Chris Wilson wrote:
> > On Mon, Jun 16, 2014 at 07:51:34PM +0200, Daniel Vetter wrote:
> > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > > index b8359f4a6dc4..dfdbf2a02844 100644
> > > --- a/drivers/gpu/drm/i915/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/intel_display.c
> > > @@ -2755,6 +2755,8 @@ intel_pipe_set_base(struct drm_crtc *crtc, int x, int y,
> > >
> > > dev_priv->display.update_primary_plane(crtc, fb, x, y);
> > >
> > > + intel_frontbuffer_flush(dev, INTEL_FRONTBUFFER_PRIMARY(pipe));
> >
> > Conceptually all of these are just intel_fb_flip_complete. It may be
> > easier in your tracking scheme to have:
> >
> > intel_fb_flip() { intel_fb_flip_prepare(); intel_fb_fip_complete(); }
>
> Yeah, this is just the direct flush for synchronous updates. Implementing
> that as a prepare+complete is imo too confusing - the entire point of
> prepare+complete is to catch an intermediate invalidates and not complete
> the flush and so only really required for async flips. Hence why I prefer
> to only do the full prepare+complete dance where needed. Otherwise there
> is nothing special about flips.

I just prefer to have the like operations having like names. The key
point here is that we just want to treat the set-plane operations as a
synchronous flip, which is distinct to the invalidate/flush operations on
an active frontbuffer.
-Chris

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Chris Wilson, Intel Open Source Technology Centre