[RFC] drm: add support for tiled/compressed/etc modifier in addfb2

[Rob Clark]

On Fri, Dec 12, 2014 at 10:30 AM, Ville Syrjälä
<ville.syrjala at linux.intel.com> wrote:
>>
>> Having them separated is still kinda nice though, for the same rationale as
>> the EGLImage import extension having them as hints. If your hardware
>> doesn't support the tiling/compression format you use, then you're going to
>> be showing absolute garbage. But if it doesn't support your exact
>> chroma-siting or YUV range request, it'll still be totally viewable, just
>> not entirely perfect. So I don't see the logic in failing these.
>
> Well, it will look nasty when switching between GL and display
> composition the GL path does the right thing an display path doesn't/
> And we already have that problem with the fuzzy alignment/scaling
> restriction stuff. So I think we will want some kind of strict flag
> somewhere to allow the user to specify that they'd rather fail the whole
> thing and fall back to GL rather than annoy the user.


another argument in favor of plane properties, I think.  This way
userspace can query what is actually possibly and we don't implicitly
give userspace the idea that display hw can handle something that it
doesn't..

BR,
-R