Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging

[Laura Abbott <labbott@redhat.com>]

On 03/09/2017 02:00 AM, Benjamin Gaignard wrote:
> 2017-03-06 17:04 GMT+01:00 Daniel Vetter <daniel@ffwll.ch>:
>> On Mon, Mar 06, 2017 at 11:58:05AM +0100, Mark Brown wrote:
>>> On Mon, Mar 06, 2017 at 11:40:41AM +0100, Daniel Vetter wrote:
>>>
>>>> No one gave a thing about android in upstream, so Greg KH just dumped it
>>>> all into staging/android/. We've discussed ION a bunch of times, recorded
>>>> anything we'd like to fix in staging/android/TODO, and Laura's patch
>>>> series here addresses a big chunk of that.
>>>
>>>> This is pretty much the same approach we (gpu folks) used to de-stage the
>>>> syncpt stuff.
>>>
>>> Well, there's also the fact that quite a few people have issues with the
>>> design (like Laurent).  It seems like a lot of them have either got more
>>> comfortable with it over time, or at least not managed to come up with
>>> any better ideas in the meantime.
>>
>> See the TODO, it has everything a really big group (look at the patch for
>> the full Cc: list) figured needs to be improved at LPC 2015. We don't just
>> merge stuff because merging stuff is fun :-)
>>
>> Laurent was even in that group ...
>> -Daniel
> 
> For me those patches are going in the right direction.
> 
> I still have few questions:
> - since alignment management has been remove from ion-core, should it
> be also removed from ioctl structure ?

Yes, I think I'm going to go with the suggestion to fixup the ABI
so we don't need the compat layer and as part of that I'm also
dropping the align argument.

> - can you we ride off ion_handle (at least in userland) and only
> export a dma-buf descriptor ?

Yes, I think this is the right direction given we're breaking
everything anyway. I was debating trying to keep the two but
moving to only dma bufs is probably cleaner. The only reason
I could see for keeping the handles is running out of file
descriptors for dma-bufs but that seems unlikely.
> 
> In the future how can we add new heaps ?
> Some platforms have very specific memory allocation
> requirements (just have a look in the number of gem custom allocator in drm)
> Do you plan to add heap type/mask for each ?

Yes, that was my thinking. 

> 
> Benjamin
> 

Thanks,
Laura