[Mesa-dev] [PATCH dri3proto v2] Add modifier/multi-plane requests, bump to v1.1

[Michel Dänzer]

On 27/07/17 04:08 PM, Nicolai Hähnle wrote:
> On 27.07.2017 03:14, Michel Dänzer wrote:
>> On 26/07/17 09:15 PM, Nicolai Hähnle wrote:
>>> On 26.07.2017 08:29, Michel Dänzer wrote:
>>>> On 25/07/17 05:28 PM, Nicolai Hähnle wrote:
>>>>> On 22.07.2017 14:00, Daniel Stone wrote:
>>>>>>
>>>>>> Given that, I'm fairly inclined to punt those until we have the grand
>>>>>> glorious allocator, rather than trying to add it to EGL/GBM
>>>>>> separately. The modifiers stuff was a fairly obvious augmentation -
>>>>>> EGL already had no-modifier format import but no query as to which
>>>>>> formats it would accept, and modifiers are a logical extension of
>>>>>> format - but adding the other restrictions is a bigger step forward.
>>>>>
>>>>> Perhaps a third option would be to encode the required pitch_in_bytes
>>>>> alignment as part of the modifier?
>>>>>
>>>>> So DRI3GetSupportedModifiers would return DRM_FORMAT_MOD_LINEAR_256B
>>>>> when the display GPU is a Raven Ridge.
>>>>>
>>>>> More generally, we could say that fourcc_mod_code(NONE, k) means that
>>>>> the pitch_in_bytes has to be a multiple of 2**k for e.g. k <= 31.
>>>>> Or if
>>>>> you prefer, we could have a stride requirement in elements or pixels
>>>>> instead of bytes.
>>>>
>>>> Interesting idea. FWIW, I suspect we'd need to support specifying the
>>>> requirement in both bytes or pixels, since one or the other alone may
>>>> not be sufficient to describe the constraints of all hardware.
>>>
>>>  From what I've seen, modifiers are always specified together with one
>>> specific format, so the bytes-per-pixel are always known, so I don't
>>> think we need both.
>>
>> The proposal adds two DRI3 extension requests for querying the list of
>> supported formats and modifiers, respectively. This suggests that the
>> supported formats and modifiers can be freely combined.
> 
> Which are these? I only saw DRI3GetSupportedModifiers, which takes both
> a window and a format argument.

You're right, I missed the format argument.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer