On Fri, Mar 28, 2014 at 06:52:50PM +0100, Daniel Vetter wrote:
On Fri, Mar 28, 2014 at 04:50:13PM +0100, Laurent Pinchart wrote:
Hi Matt,
Thank you for the patch.
On Thursday 27 March 2014 17:44:29 Matt Roper wrote:
Ensure that existing driver loops over all planes do not change behavior when we begin adding new types of planes (primary and cursor) to the DRM plane list in future patches.
Cc: Laurent Pinchart laurent.pinchart+renesas@ideasonboard.com Signed-off-by: Matt Roper matthew.d.roper@intel.com
Acked-by: Laurent Pinchart laurent.pinchart@ideasonboard.com
I have a question though. The patch set introduces three plane types, OVERLAY, PRIMARY and CURSOR. What should a driver that has no concept of primary plane do ? Expose all planes as OVERLAY planes only ?
It's a matter of backwards compat with old userspace. primary/cursor are simply ways to tell the drm core which planes to use to forward the legacy cursor crtc and which plane will be used for the framebuffer in setCrtc.
So until we have the new atomic interface ready your driver kinda needs to expose at least a primary plane, otherwise there's no way to even switch on the crtc.
But besides this backwards compat issue there's no difference and you can specify whatever plane you want as primary/cursor (or none if you don't care about old userspace).
Well the NULL primary plane probably needs a bit of work on top of Matt's patch series here ... -Daniel