[Intel-gfx] [PATCH 0/9] drm/i915: Plane rotation support

[Daniel Vetter]

On Mon, Sep 30, 2013 at 7:46 PM, Rob Clark <robdclark at gmail.com> wrote:
> I guess the main thing I care about is that we don't advertise things
> to userspace that we can't actually do.  I'm not sure what other hw
> out there supports rotation in hw in some form or another, but it
> might be a good time to hear from 'em about whether these property
> values work for them or not.

Hm, I've thought the plan was to let userspace figure that out with a
dry-run flag, and if a certain configuration doesn't work it needs to
fall back to rendering-based compositioning for the given surface. I
don't think there's really much more we can do for fully generic
compositors.

Tha might leave strange hw in the dust where planes aren't symmetric
in capabilities and hence a simple linear walk over surfaces/planes,
ordered by bw-savings or so, yields extermely bad surface->plane
assignements. But  my impression is that hw is moving to unified
stacks of planes so I hope we can punt on solving this in a generic
way (and resort to quick platform hacks in userspace where it's really
needed to hit e.g. video playback power targets).
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch