Date: Thu, 28 Apr 2016 14:55:25 -0300
From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
To: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>, Gustavo Padovan <gustavo@padovan.org>,
        Daniel Stone <daniel@fooishbar.org>,
        Greg Hackmann <ghackmann@google.com>,
        Daniel Stone <daniels@collabora.com>,
        Riley Andrews <riandrews@android.com>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Arve =?iso-8859-1?B?SGr4bm5lduVn?= <arve@android.com>,
        John Harrison <John.C.Harrison@intel.com>
Subject: Re: [RFC v2 5/8] drm/fence: add in-fences support
Message-ID: <20160428175525.GA3502@joana>
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 <CAPj87rOfhDr14xFCH1A+BM3u_EfS66cmSTXcs32PUJrhH8nfLg@mail.gmail.com>
 <20160428143644.GA3496@joana>
 <20160428165619.GD4329@intel.com>
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2016-04-28 Ville Syrj?l? <ville.syrjala@linux.intel.com>:

> On Thu, Apr 28, 2016 at 07:43:16PM +0200, Daniel Vetter wrote:
> > On Thu, Apr 28, 2016 at 6:56 PM, Ville Syrj?l?
> > <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?

We can just not return FENCE_FD on get_props, that would make it
write-only.

	Gustavo