[Mesa-dev] GBM backend dynamic dispatch method

[Jammy Zhou]

2016-05-13 12:39 GMT+08:00 Nicolai Hähnle <nhaehnle at gmail.com>:

> On 12.05.2016 20:20, Jammy Zhou wrote:
>
>>
>>
>> 2016-05-12 17:39 GMT+08:00 Michel Dänzer <michel at daenzer.net
>> <mailto:michel at daenzer.net>>:
>>
>>     On 12.05.2016 17:58, Yu, Qiang wrote:
>>     > Oh, what a crazy idea. So you mean it can work like this?
>>     >
>>     > 1. use the libgbm/gbm_dri/libEGL/libGLES from mesa which will load
>>     > radeonsi_dri.so
>>     >
>>     > 2. libGL/amdgpu_dri.so from amdgpu-pro
>>
>>     glamor uses libEGL/GBM and libGL, so this could only work with Mesa's
>>     libGL (or the GLVND one in the future). Can amdgpu_dri.so work with
>>     Mesa's libGL right now?
>>
>>
>> I think amdgpu_dri.so is not completely compatible with Mesa's libGL
>> (considering some special feature requirements for amdgpu-pro and Mesa's
>> evolving). Another problem is that Mesa's libgbm cannot share necessary
>> buffer attributes (such as tiling info, etc) with amdgpu_dri.so at this
>> moment.
>>
>
> I think the long-term plan for such attributes is passing them via
> amdgpu_bo_metadata (which is defined in libdrm's amdgpu.h). This metadata
> is read and written directly through libdrm_amdgpu, and so libgbm doesn't
> have to be involved as far as I can see.
>

Yes, amdgpu_bo_metadata is exactly one good place for such kind of
information. But IMHO there are still several things to take care. Did I
miss something?
- Same meta data definition ("umd_metadata" field) should be used by
radeonsi and amdgpu-pro.
- We need some way to translate gbm_bo or EGLImage into amdgpu_bo, so that
libdrm_amdgpu interfaces can be used.

Regards,
Jammy


>
> Or is there some use-case that I'm forgetting where libgbm _does_ need
> those attributes?
>
> Cheers,
> Nicolai
>
>
>>
>>     Also, I'm afraid there might still be cases where amdgpu-pro supports
>>     new hardware before radeonsi, in which case amdgpu_dri.so needs to
>>     support GBM for glamor and EGL in general.
>>
>>
>> IIRC radeonsi can support Southern Islands and later ASICs. I don't
>> think amdgpu-pro can support pre-GCN products easily, given current
>> amdgpu kernel driver support.
>>
>>
>>
>>     Also note that Nvidia developers were talking about possibly creating
>> an
>>     nvidia specific GBM backend recently on the wayland-devel mailing
>> list.
>>
>>
>> Will nvidia open source their code for GBM backend?
>>
>>
>>
>>     --
>>     Earthling Michel Dänzer               | http://www.amd.com
>>     Libre software enthusiast             |             Mesa and X
>> developer
>>     _______________________________________________
>>     mesa-dev mailing list
>>     mesa-dev at lists.freedesktop.org <mailto:mesa-dev at lists.freedesktop.org
>> >
>>     https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>>
>>
>>
>>
>> _______________________________________________
>> mesa-dev mailing list
>> mesa-dev at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>>
>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20160513/ba450364/attachment.html>