[Mesa-dev] GL4.5 or bust...

[Ilia Mirkin]

On Sun, May 15, 2016 at 8:25 PM, Martin Peres <martin.peres at free.fr> wrote:
> On 16/05/16 02:55, Jason Ekstrand wrote:
>> On May 15, 2016 2:01 PM, "Martin Peres" <martin.peres at free.fr
>> <mailto:martin.peres at free.fr>> wrote:
>> >
>> > On 15/05/16 23:54, Ilia Mirkin wrote:
>> >>
>> >> On Sun, May 15, 2016 at 4:32 PM, Dave Airlie <airlied at gmail.com
>> >> <mailto:airlied at gmail.com>> wrote:
>> >>>
>> >>> So I said this on irc over the weekend and it seemed like we had some
>> >>> consensus on holding off 12.0 until we could announce 4.5 on some
>> >>> hardware. This assumes the FP64 stuff is going in at least.
>> >>>
>> >>> So I decided to roll out the proposal here, which is that we finish
>> >>> GL4.5 features off for at least Skylake I think.
>> >>>
>> >>> So what is needed/missing: please add as you see fit.
>> >>>
>> >>> a) robustness - radeonsi has some bits of this. We need to get
>> >>> KHR_robustness bits, that I think Kayden has patches started for, and
>> >>> i965 needs to ensure it uses robust buffer stuff. I don't think this
>> >>> one in unobtainable.
>> >>>
>> >>> b) cull_distance - I merged something, it broke, I'll fix it today,
>> >>> job done.
>> >>>
>> >>> c) enhanced_layouts - So tarceri has posted patches, we know that to
>> >>> do it properly we probably need to rip up attribute packing and
>> >>> rewrite it, however if Kayden thinks what tarceri has done is
>> >>> functional enough for now, we could merge the final pieces and work on
>> >>> perfection later.
>> >>>
>> >>> d) SIMD32 for i965 compute shaders - this is probably the most unknown
>> >>> to me, curro says he's got some patches, that need to rebase onto FP64
>> >>> when it lands, assuming he can do that, and reviewers can get on top
>> >>> of things, and we possibly only enable SIMD32 in the corner cases
>> >>> initially, it might be possible to get this landed.
>> >>>
>> >>> Have I missed anything? Should we go for it?
>> >>
>> >> The bugs that get triggered when you expose GL 4.3+ to UE4 games. Some
>> >> are ours, some are theirs. Someone needs to sign up for this work.
>> >>
>> >> Also, I'd like to mention that ES 3.2 is pretty close as well. But
>> >> probably not close enough to squeeze in here. Ian has started working
>> >> on the OES_shader_io_blocks bits of it (which IMO shouldn't be too bad
>> >> for someone who knows what all GLSL allows and what it doesn't), which
>> >> was the last remaining big chunk. I have preliminary patches for core
>> >> support of advanced blending, the rest should all be easy.
>> >>
>> >>> For radeonsi, I think the only other missing bit is qbo and
>> >>> clear_texture, which may or may not make it in time.
>> >>
>> >> I'm in favor of this plan. Nouveau should be ready for Fermi and
>> >> Kepler once Samuel's images patches for Fermi land (mostly reviewed,
>> >> had a couple of nits). Maxwell will be missing tess and images, and
>> >> it's unlikely that either of those will get done in a reasonable
>> >> period of time. I think we can just flip robustness on... probably not
>> >> meeting all the provisions of that spec, but ... meh.
>> >>
>> >> That said, we should put a cap on this timewise - if e.g. it becomes
>> >> clear that SIMD32 will take a long time (I think the biggest potential
>> >> issue of the batch), we should just cut a release. Maybe a 1 month
>> >> cap?
>> >
>> >
>> > Yeah, a cap of 1 month delay compared to the initial plan or 1
>> > week after the driver reaching 4.5 in master, whatever happens
>> > first.
>>
>> I agree with a time limit if we're going to do this. Another suggestion
>> that had been made is to go ahead with the release and then plan to release
>> mesa 13 as soon as we get 4.5. I'm personally OK with either.
>> --Jason
>>
> Let's see if it would prevent some superstitious people from updating :p
>
> In any case, I agree with Jason. Mesa is released often-enough and things
> will get a little buggy as games suddenly start exercising mesa is funny
> ways. So, let's not rush it out if it cannot reach the quality needed and
> just release another major version when it is ready.

Of course the way to discover that games/applications suddenly start
exercising mesa in funny ways is to do a release... a bit of a catch
22, wouldn't you say? I don't think developers and the users of
mesa-git are really going to be enough to get all the kinks out. And
the RC period should be sufficient time to fix any major issues that
pop up.

  -ilia