[PATCH 1/2] drm: Make fbdev inherit the crtc's initial rotation

[Ville Syrjälä]

On Wed, Apr 26, 2017 at 02:28:32PM +0200, Bastien Nocera wrote:
> On Mon, 2017-04-24 at 15:48 +0300, Ville Syrjälä wrote:
> > 
> <snip>
> 
> > > I've a patch for iio-sensor-proxy which fixes the rotation under
> > > Xorg /
> > > Wayland when using a desktop environment which honors iio-sensor-
> > > proxy's
> > > rotation detection:
> > > https://github.com/hadess/iio-sensor-proxy/pull/162
> > 
> > Or is it just this thing that clobbers what the DDX inherited from
> > the
> > kernel as the initial rotation?
> 
> I think it's mostly got to do with the compositor (or X) not knowing
> what "normal" or "0 degrees rotation" corresponds to.

Well, there are really two cases to consider:

1. BIOS/whatever configures display hardware rotation in a way
   that matches the orientation of the physical display
2. BIOS didn't do that. Either the hardware can't do what
   would be required, or the BIOS just chose not to do it.

Case 1 should work with these patches as long as the DDX will set up the
initial randr rotation to match what it read out from the kms rotation
property of the primary plane.

Case 2 can't work without some mechanism to query the orientation
of the display from the firmware/etc.

-- 
Ville Syrjälä
Intel OTC