[libcamera-devel] [PATCH v3 24/30] cam: drm: Set per-plane offsets when creating DRM frame buffer

[Laurent Pinchart]

Hi Kieran,

On Tue, Sep 07, 2021 at 12:43:43PM +0100, Kieran Bingham wrote:
> On 06/09/2021 23:56, Laurent Pinchart wrote:
> > Now that libcamera supports per-plane offsets, pass the values to
> > drmModeAddFB2().
> 
> Any further implications from this?
> Will there be a specific effect? or does it just mean that DRM can
> allocate buffers for more of our formats?

There's no particular implication other than the fact that the KMS sink
in cam is now fixed for multi-planar formats :-) Without the offset it
wouldn't render NV12 correctly when planes are stored in the same
dmabuf.

We still allocate buffers using the FrameBufferAllocator even when using
the KMS sink, so this isn't related to allocation.

> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois at ideasonboard.com>
> > ---
> >  src/cam/drm.cpp | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/src/cam/drm.cpp b/src/cam/drm.cpp
> > index ac47b8bd3287..d5a75d039fd8 100644
> > --- a/src/cam/drm.cpp
> > +++ b/src/cam/drm.cpp
> > @@ -623,7 +623,7 @@ std::unique_ptr<FrameBuffer> Device::createFrameBuffer(
> >  		fb->planes_.push_back({ handle });
> >  
> >  		handles[i] = handle;
> > -		offsets[i] = 0; /* TODO */
> > +		offsets[i] = plane.offset;
> >  		++i;
> >  	}
> >  

-- 
Regards,

Laurent Pinchart