[alsa-devel] HDMI+SND_JACK_AVOUT

[Takashi Iwai]

On Mon, 15 May 2017 14:29:20 +0200,
Pierre-Louis Bossart wrote:
> 
> Hi,
> Does anyone know the reason why the Intel/HDaudio HDMI layers use
> SND_JACK_AVOUT as a jack type?

Because it's really an audio output on the video jack?

> This value is composite and ends up
> having the side effect of sending 2 independent input events to
> userspace (SW_LINEOUT_INSERT and SW_VIDEOOUT_INSERT) and confusing the
> Android logic which deals with wired accessories. Shouldn't we use
> just SND_JACK_VIDEOOUT instead? What is the reason or rationale behind
> the use of LINEOUT for HDMI/DP jack events?

The LINEOUT combo is just an implementation detail, and user-space is
supposed to interpret these two combo as a single AV detection.  It's
similar like the headset.

But I agree that it's a bit confusing as of now.  Since there is only
one user of SND_JACK_VIDEOOUT (omap/rx51) and the driver also assumes
it being AV jack (the control is named as "AV Jack"), I guess we can
merge these two into a single one.

Our jack interface is clearly for audio, so AV is equivalent with
video, after all.


thanks,

Takashi