[PATCH 4/7] drm/meson: plane: add support for AFBC mode for OSD1 plane

[Neil Armstrong]

On 15/10/2019 13:18, Brian Starkey wrote:
> Hi Neil,
> 
> On Fri, Oct 11, 2019 at 02:07:01PM +0200, Neil Armstrong wrote:
>> On 11/10/2019 12:56, Brian Starkey wrote:
>>> Hi,
>>>
>>> On Fri, Oct 11, 2019 at 11:14:43AM +0200, Neil Armstrong wrote:
>>>> Hi Brian,
>>>>
>>>> On 11/10/2019 10:41, Brian Starkey wrote:
>>>>> Hi Neil,
>>>>>
>>>>> On Thu, Oct 10, 2019 at 03:41:15PM +0200, Neil Armstrong wrote:
> 
> [snip]
> 
>>>> You'll have to tell us if the closed libMali handling AFBC would accept
>>>> ARGB8888 as format to render with AFBC enabled, if not you're right
>>>> I'll discard XRGB8888/ARGB8888 for AFBC buffers completely.
>>>>
>>>> But it the libMali chooses tt generate an ARGB8888 buffer whatever
>>>> ARGB8888/XRGB8888/ABGR888/XBGR888 is asked, then no I'll keep it that way.
>>>>
>>>
>>> Yeah, I'll try and get clarity on this. It's not at all clear to me
>>> either. When you say "accept ARGB8888 as format to render with AFBC
>>> enabled", which API are you referring to, just so I can be clear? Do
>>> you have an example of some code you're using to render AFBC with the
>>> GPU blob?
>>
>> Let's take kmscube using EGL and GBM.
>>
>> The buffer is allocated using gbm_surface_create_with_modifiers(),
>> but the gbm implementation is vendor specified.
>>
>> Then the surface is passed to eglCreateWindowSurface().
>> Then the format is matched using eglGetConfigAttrib() with the
>> returned configs.
>>
>> Here support on the gbm and EGL implementation.
>>
> 
> Is this a use-case that works on your platform today?

Amlogic gave ma a libMali for miniGBM with AFBC enabled, but I haven't
been able to enable AFBC yet.

> 
> I went and asked around. An Arm gbm implementation supporting AFBC
> will reject AFBC allocations for orders other than (DRM-convention)
> BGR.

I trust you on this point, thanks for asking around.

Neil

> 
> Thanks,
> -Brian
>