[PATCH 0/9] drm/i915: Plane rotation support
ville.syrjala at linux.intel.com
Mon Sep 30 11:36:59 PDT 2013
On Mon, Sep 30, 2013 at 08:21:33PM +0200, Daniel Vetter wrote:
> 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
Yeah, if no one comes up with anything better, the trial and error
approach is the plan in my mind.
But in case the hardware never ever supports certain property/value I
think we shouldn't expose it. Like 90/270 degree rotation in case of
> 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).
Right. If someone has really specific needs I think they can just go
and write their own compositor (or plugin if the compositor in question
has such things).
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