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Date: Thu, 28 Apr 2016 20:51:24 +0300
From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= <ville.syrjala@linux.intel.com>
To: Daniel Vetter <daniel@ffwll.ch>
Cc: Gustavo Padovan <gustavo@padovan.org>, Daniel Stone <daniel@fooishbar.org>,
        Greg Hackmann <ghackmann@google.com>,
        Gustavo Padovan <gustavo.padovan@collabora.co.uk>,
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        John Harrison <John.C.Harrison@intel.com>
Subject: Re: [RFC v2 5/8] drm/fence: add in-fences support
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On Thu, Apr 28, 2016 at 07:43:16PM +0200, Daniel Vetter wrote:
> On Thu, Apr 28, 2016 at 6:56 PM, Ville Syrjälä
> <ville.syrjala@linux.intel.com> wrote:
> >>  - better for tracing, can identify the buffer/fence promptly
> >
> > Can fences be reused somehow while still attached to a plane, or ever?
> > That might cause some oddness if you, say, leave a fence attached to one
> > plane and then do a modeset on another crtc perhaps which needs to turn
> > the first crtc off+on to reconfigure something.
> 
> Fences auto-disappear of course and don't stick around when you
> duplicate the drm_plane_state again. I still don't really get the real
> concerns though ...

Properties that magically change values shouldn't exist IMO. I guess if
you could have write-only properties or something it migth be sensible?

> In the end it's purely a transport question, and
> both ABI ideas work out semantically exactly the same in the end. It's
> just that at least in my opinion FENCE_FD prop is a lot more
> convenient.
> -Daniel
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch

-- 
Ville Syrjälä
Intel OTC