[Mesa-dev] [RFC v2 0/5] DRI3 v1.2, ANV X11 explicit fences

[Louis-Francis Ratté-Boulianne]

Hi,

On Thu, 2017-09-28 at 17:00 +0100, Emil Velikov wrote:
> Hi Louis-Francis,
> 
> On 28 September 2017 at 09:25, Louis-Francis Ratté-Boulianne
> <lfrb at collabora.com> wrote:
> > This patchset makes use of Jason Ekstrand's recent work on SYNC_FD
> > semaphores and DRI3 v1.2 support for DMA fences:
> > https://lists.x.org/archives/xorg-devel/2017-September/054770.html
> > 
> > This is the second version of this patchset. For more context, see:
> > https://lists.freedesktop.org/archives/mesa-dev/2017-August/168201.
> > html
> > 
> > The main changes compared to previous iteration are:
> > 
> >  - DMA fences are now split to a different DRI3 version (v1.2)
> > 
> >  - Check if Present protocol has the right version (v1.2)
> > 
> >  - Correctly initialize the fences and do the right thing when
> >    the X server doesn't support explicit fencing.
> > 
> > The related Git repositories are (branch: rfc/2017-09/x11-fences):
> > 
> 
> A few somewhat high-level tips:
>  - please mention why we went from DRI3 1.2, what happened with 1.1
> I recall some concerns from X developers, but having a brief and/or
> links will be appreciated

I don't think there is any public trace of that, but Daniel Stone
mentioned to me that a X developer would indeed prefer if multi-
plane/modifiers features and DMA fences were in two separate DRI3
releases.
> 
>  - with the 1.2 the have_dri3... booleans start getting a bit silly
> Perhaps store the version itself or rename the flag -
> have_dri3_fences or alike

Sure thing.

>  - the commit messages are quite sparse

Sligthly improved now.

>  - the #if XCB_FOO_VERSION checks are a bad idea
> As soon as the X/Mesa (and XCB of course) devs are happy with the
> approach, let's merge the XCB patches are roll a release.

Yes, you already mentioned that and the defines will indeed disappear
once we're ready to roll into a release. I still put them in there for
now just to be sure someone doesn't try to test the branch without the
appropriate dri3/present proto versions.

I won't re-submit rightawathe X11 fences patchset right away for these
minor changes though. You can check my 'rfc/2017-10/x11-fences' branch
[0].

[0] https://git.collabora.com/cgit/user/lfrb/mesa.git/log/?h=rfc/2017-1
0/x11-fences

Thanks,

--
Louis-Francis
Collabora