[alsa-devel] HDMI+SND_JACK_AVOUT
Hi, Does anyone know the reason why the Intel/HDaudio HDMI layers use SND_JACK_AVOUT as a jack type? 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? Thanks -Pierre
http://elixir.free-electrons.com/linux/latest/ident/SND_JACK_AVOUT
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
participants (2)
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Pierre-Louis Bossart
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Takashi Iwai