[Mesa-dev] gralloc_drm_pipe

[Rob Clark]

On Fri, Mar 4, 2016 at 2:43 PM, Thomas Hellstrom <thellstrom at vmware.com> wrote:
> On 03/04/2016 07:07 PM, Rob Clark wrote:
>> On Fri, Mar 4, 2016 at 12:59 PM, Rob Clark <robdclark at gmail.com> wrote:
>>> So, I've been advocating that for android, gallium drivers use
>>> gralloc_drm_pipe, since with android it seems like you end up with
>>> both gralloc and libGL in the same process, and having both share the
>>> same pipe_screen avoids lots of headaches with multiple gem handles
>>> pointing to same underlying buffer.
>>>
>>> But the awkward thing is that gralloc_drm_pipe is using gallium APIs
>>> that aren't particularly intended to be used out-of-tree.  Ie. not
>>> really stable APIs.  At the time, the thing that made sense to me was
>>> to pull drm_gralloc into mesa.  But at the time, there were no
>>> non-mesa users of drm_gralloc, which isn't really true anymore.
>>>
>>> Maybe what makes more sense now is to implement a gralloc state
>>> tracker, which exposes a stable API for drm_gralloc?  It would mostly
>>> be a shim to expose gallium import/export/transfer APIs in a stable
>>> way, but would also be where the code that figures out which driver to
>>> use to create/get the pipe_screen.
>> and actually, we might just be able to use XA state tracker for this..
>> I think it exposes all the necessary import/export/etc stuff that
>> gralloc would need..
>>
>> BR,
>> -R
>>
> and it was created for a very similar purpose, except that we also
> needed some
> render functionality, enough to composite surfaces.

right, and since we have the ability to import/export dmabuf handles,
I think it is a superset of what is needed.  (gralloc is using blits
instead of flips for vmwgfx, for reasons I don't fully understand..
but XA can do these blits and more, so we are still good there)

BR,
-R