[alsa-devel] [RFC] ASoC: snd_soc_jack for HDMI audio: does it make sense?
tiwai at suse.de
Tue Aug 21 07:28:34 CEST 2012
At Mon, 20 Aug 2012 20:47:17 -0500,
Ricardo Neri wrote:
> I have been working on prototypes for the ASoC OMAP HDMI audio driver to
> propagate events from the HDMI output (e.g., display getting
> enabled/disabled/suspended). This for the users of the driver to react
> to such events. For instance, if the display is disabled or disconected,
> audio could be stopped, rerouted or whatever other decision the user
> makes. This is needed because, if, for instance, the HDMI IP goes off,
> audio will stall and the audio users will only see a "playback write
> error (DMA or IRQ trouble?)"
> In my prototypes I have used snd_soc_jack for this purpose and I have
> some questions:
> *I see snd_soc_jack is used mostly for headsets and microphones with
> actual external mechanical connections. Strictly, in my case I propagate
> events originated by the OMAP display driver (changes in the power
> state), and not from external events. Some of these events are generated
> from an actual HDMI cable connection/disconnection, though.
> *Maybe the event should be propagated by omapdss/omapdrm/drm and the
> entity in charge of the audio policy should listen those events instead.
> *I do see SND_JACK_VIDEOOUT and SND_JACK_AVOUT types so maybe it is
> feasible for an audio driver to report events from an AV output.
> I was wondering about how much sense does it make to you guys use a
> snd_soc_jack in this case?
HD-audio already uses the generic jack event for the HDMI/DP
connection change notification as well, so I think it would make sense
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