RPI HDMI audio for linux upstream tree.

[Michael Zoran]

On Tue, 2016-10-18 at 10:59 -0700, Eric Anholt wrote:
> Michael Zoran <mzoran at crowfest.net> writes:
> 
> > Hi, 
> > 
> > I'm aware of the effort to upstream the vchiq driver from the
> > downstream RPI linux tree.  In fact, I'm working on a patch set to
> > allow the vchiq driver to be compiled for arm64.  I should be able
> > to
> > submit this shortly.
> > 
> > The question I was wondering is if any effort is being made to get
> > HDMI
> > audio for the RPI upstreamed?  IMHO, I'm not sure if vchiq has a
> > whole
> > lot of value without the audio driver being added as well.   I'm
> > fact,
> > to test my patches I've been copying the driver back to the
> > downstream
> > tree just so I have a test mechanism.
> > 
> > I would also like to add that I just so happen to have a arm64 port
> > of
> > the HDMI audio driver that seems to work quite well.   I'm able to
> > play
> > movies through VLC and watch videos from Youtube on my RPI3 running
> > in
> > arm64 mode.
> 
> We should really be driving HDMI audio entirely from the ARM.  I
> haven't
> scoped out the native stuff yet, but I expect it will be 80%
> bikeshedding DT bindings.  I'd consider firmware-based HDMI audio to
> be
> a temporary solution until we get ARM-side HDMI audio to work.
> 
> That said, something temporary may be worth doing until we can get
> the
> open source stuff done.  Want to look into putting it into staging?
> 
> My motivation for VCHIQ was to get media driver (camera, video
> decode,
> video encode) support.  I don't think we can get media fully opened,
> so
> VCHI is our only route to supporting it currently.

I would be interested in staging the audio driver even if it is only a
temp fix.  When combined with the new 3D video driver, it would add a
lot of value to the upstream code.