[Intel-gfx] [RFC 0/4] Wire gen9 cursor interface to universal plane registers

[Chris Wilson]

On Wed, Oct 26, 2016 at 03:51:27PM -0700, Matt Roper wrote:
> Gen9 has a traditional cursor plane that is mutually exclusive with the
> system's top-most "universal" plane; it seems likely that two planes are really
> a single shared hardware unit with two different register interfaces.  Thus far
> i915 has exposed a cursor plane to userspace that's hooked up to the old-style
> cursor registers; we just pretended that the top-most universal plane didn't
> exist and reported one fewer "sprite/overlay" planes for each pipe than the
> platform technically has.  Let's switch this around so that the cursor exposed
> to userspace is actually wired up to the previously-unused top-most universal
> plane registers.  With this change we'll still present the same cursor ABI to
> userspace that we always have, but internally we'll just be programming a
> different set of registers and doing so in a way that's more consistent with
> how all the other gen9 planes work --- less cursor-specific special cases
> throughout the code.

But you still report it as PLANE_TYPE_CURSOR right? Otherwise those that
both expose all the overlay planes and use the legacy cursor abi will be
trying to use that plane simultaneously via two different paths (and
clients). Or is this another cap?
	DRM_CLIENT_CAP_UNIVERSAL_PLANES = no-legacy-cursor-abi
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre