[PATCH 04/14] drm/exynos: remove struct *_win_data abstraction on planes

[Daniel Vetter]

On Thu, Feb 05, 2015 at 11:37:13AM +0900, Joonyoung Shim wrote:
> Hi Daniel,
> 
> On 02/04/2015 11:28 PM, Daniel Vetter wrote:
> > On Wed, Feb 04, 2015 at 04:44:12PM +0900, Joonyoung Shim wrote:
> >> Hi,
> >>
> >> On 02/04/2015 04:14 AM, Gustavo Padovan wrote:
> >>> From: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
> >>>
> >>> struct {fimd,mixer,vidi}_win_data was just keeping the same data
> >>> as struct exynos_drm_plane thus get ride of it and use exynos_drm_plane
> >>> directly.
> >>>
> >>> It changes how planes are created and remove .win_mode_set() callback
> >>> that was only filling all *_win_data structs.
> >>>
> >>
> >> I commented already on prior patch.
> > 
> > I think you don't quite understand how this primary/overlay plane stuff
> > works in drm core. The entire point of the drm core primary plane is to
> > work _exactly_ like an overlay plane and allow userspace to mangle the
> > primary plane configuration through the overlay plane. The only reason we
> > have primary planes is so that old userspace keeps working.
> > 
> 
> Right, i misunderstood a bit because exynos hw drivers have dependency
> of zpos(hw overlay position).
> 
> Current exynos drm driver has each primary plane of hw drivers and five
> overlay planes. The primary plane is fixed on default hw overlay and all
> overlay plane can map to all hw overlays using specific zpos property of
> exynos drm plane.
> 
> Gustavo approach will include specific hw overlay data in overlay plane
> and hw driver keeps overlay planes to array by zpos order. But current
> zpos of overlay plane is 0 always if user doesn't modify it, so hw
> driver will use only hw overlay data of primary plane always even if
> user want to use overlay plane.
> 
> If user is modified zpos of overlay plane, hw driver can get wrong hw
> overlay data from different overlay plane because hw driver keeps
> overlay planes by zpos order.

Yeah I noticed the zpos fun when hacking around too. Exynos should
probably switch defaults so that overlays are visible by default. And we
need to standardize the zpos property so that other drivers can use it
too.

But that doesn't change anything with the primary plane just being a
special plane from the sw side (backwards compat), for exynos hw they all
look the same.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch