[alsa-devel] [PATCH] ALSA: HDA: Add jack detection for HDMI

pl bossart bossart.nospam at gmail.com
Wed May 18 17:43:36 CEST 2011

>> > A simple approach would be adding a control element containing
>> > byte-array of ELD/EDID.
>> Are there any examples of such controls? Or are we talking about a new
>> kind of control?
> Look for SNDRV_CTL_ELEM_TYPE_BYTES.  Some codecs provide these.

I started doing some work on this, adding a persistent 256-byte buffer
to store the ELD data instead of dynamically allocating and freeing
the buffer. I am kind of lost with the controls though, never looked
at this part of ALSA before.
In all the HDA code, all controls have an IFACE_MIXER type, while all
the code that uses ELEM_TYPE_BYTES the type is IFACE_PCM. Does this
matter at all?
Likewise, there's a 'generic_hdmi_build_controls' routine in which I
could add the ELD control, but it uses cvt structures. I think it
would make more sense to relate ELD controls to pins, as done with the
proc information.
Quite a learning experience...

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