Hi Simon,
Le lun. 29 mars 2021 à 14:11, Simon Ser <contact@xxxxxxxxxxx> a écrit
:
On Monday, March 29th, 2021 at 4:07 PM, Maxime Ripard
<maxime@xxxxxxxxxx> wrote:
Since it looks like you have two mutually exclusive planes, just
expose
one and be done with it?
You can expose the other as an overlay. Clever user-space will be able
to figure out that the more advanced plane can be used if the primary
plane is disabled.
But yeah, I don't think exposing two primary planes makes sense. The
"primary" bit is just there for legacy user-space, it's a hint that
it's the best plane to light up for fullscreen content. It has no
other
significance than that, and in particular it doesn't mean that it's
incompatible with other primary planes.
Yes, from what I understood when writing the driver, there is not much
of a difference with primary vs. overlay planes when dealing with the
atomic DRM API, which I used exclusively.
Making the second plane an overlay would break the ABI, which is never
something I'm happy to do; but I'd prefer to do it now than later.
I still have concerns about the user-space being "clever" enough to
know it can disable the primary plane. Can e.g. wlroots handle that?
Cheers,
-Paul
