[Intel-gfx] [PATCH 10/12] drm: Don't allow multiple buffers fb with stereo modes

[Damien Lespiau]

On Tue, Sep 17, 2013 at 11:20:46AM +0300, Ville Syrjälä wrote:
 > +++ b/drivers/gpu/drm/drm_crtc.c
> > @@ -2131,6 +2131,17 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
> >  			goto out;
> >  		}
> >  
> > +		/*
> > +		 * Do not allow the use of framebuffers consisting of multiple
> > +		 * buffers with stereo modes until all the details API details
> > +		 * are fleshed out (eg. interaction with drm_planes, switch
> > +		 * between a 1 buffers and a 2 buffers fb, ...)
> > +		 */
> > +		if (fb->num_buffers > 1 && drm_mode_is_stereo(mode)) {
> > +			ret = -EINVAL;
> > +			goto out;
> > +		}
> 
> This would prevent planar buffers in stereo modes. I'm think we just
> ignore the matter for now and let drivers deal with it. We don't have
> enough handles anyway for planar stereo, so maybe we even want to add
> separate left/right fb attachment properties to the planes instead of
> tying it up in inside a single fb. Or we cook up addfb3 when we hit
> this problem for real. I think we'd anyway need some kind of flag for
> the fb if it contains both left and right buffers.

I'm quite happy to ignore 3 planes YUV stereo fbs for now :) (2 planes
YUV stereo fbs still fit!).

Are you fine with this test though, or do you mean ignore the whole
matter of forbidding this case (or just the multiplane stereo fb case)?
I was just thinking that I missed the addition of this check in the page
flip ioctl.

-- 
Damien