[Intel-gfx] [PATCH 12/15] drm: RIP mode_config->rotation_property

[Ville Syrjälä]

On Tue, Oct 18, 2016 at 11:13:53AM +0300, Laurent Pinchart wrote:
> Hi Daniel,
> 
> On Tuesday 18 Oct 2016 09:36:23 Daniel Vetter wrote:
> > On Tue, Oct 18, 2016 at 01:38:05AM +0300, Laurent Pinchart wrote:
> > > On Friday 22 Jul 2016 16:43:13 ville.syrjala at linux.intel.com wrote:
> > >> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > >> 
> > >> Now that all drivers have been converted over to the per-plane rotation
> > >> property, we can just nuke the global rotation property.
> > >> 
> > >> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > 
> > > Stupid question, but how does this work when the hardware supports global
> > > rotation only, not per-plane rotation ?
> > 
> > Does that exist? If so I guess we get to add a rotation property to CRTCS
> > (and update docs and all that).
> 
> I have a hardware composer that performs rotation on the output side. At the 
> moment it doesn't support rotation when used with the display, but I wouldn't 
> rule that out in future SoC versions. So I'm not aware of any use case for a 
> rotation property on the CRTC at the moment, I just wanted to make sure we 
> have a path forward.

I even implemented that for i915 long ago by having it rotate all the
planes (+ adjust their coordinates appropriately). But people weren't
too keen on putting that in, so I dropped it.

https://lists.freedesktop.org/archives/intel-gfx/2014-February/040053.html

The only bigger snafu here is omap, which already has a rotation property
on the crtc, except it actually only rotates the primary plane. So
when/if someone adds a real crtc rotation property it has to be called
something else that "rotation". I think I settled on "crtc-rotation"
judging what I have in my last branch on that topic.

-- 
Ville Syrjälä
Intel OTC