[alsa-devel] [PATCH v7.1 00/19] Rework OMAP4+ HDMI audio support

[Jean-Francois Moine]

On Thu, 13 Nov 2014 10:05:28 +0200
Tomi Valkeinen <tomi.valkeinen at ti.com> wrote:
	[snip]
> I don't have much knowledge of the asoc architecture, so I probably
> can't comment much on the sound/ side design. For me the most important
> things are that 1) it works 2) I can easily unload/load the modules
> (which was broken in some of the earlier versions).
> 
> As a more general discussion item, I'm still wondering why it feels like
> we (OMAP) are doing something totally new here. I'd imagine that almost
> every device with HDMI would need both video and audio side support, and
> those sides need to work together. And the audio side would need to get
> notified of things like cable disconnect (i.e. the video stream is
> stopped -> audio must be stopped also). But if I've understood right,
> there was no similar existing code to be found.

I recently posted a patch on the HDMI CODEC to interface a HDMI
transmitter
http://mailman.alsa-project.org/pipermail/alsa-devel/2014-October/082745.html
and I saw only a few dependencies between the 2 subsystems:

- the CODEC must know the transmitter parameters (DAIs - static -,
  audio constraints - dynamic -),

- the CODEC must alert the transmitter on audio start and stop.

I don't think that stopping audio streaming on HDMI disconnection is
useful. I even let audio streaming start when the HDMI cable is
disconnected.

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