[alsa-devel] HDA Intel ALC889A optical optical spdif in

[René Rebe]

Hi,

On Apr 21, 2017, at 20:01, Takashi Iwai <tiwai at suse.de> wrote:

> On Fri, 21 Apr 2017 19:22:16 +0200,
> René Rebe wrote:
>> 
>> On Apr 21, 2017, at 18:37, René Rebe <rene at exactcode.de> wrote:
>> 
>>> Hello again,
>>> 
>>> so I checked the MacBook schematics and it looks like the optical input should be directly connected to pin 47 (GPIO3/SPDIFIN)
>>> 
>>> Maybe EAPD get’s accidentally / wrongly enabled? - Maybe someone can point me how to double check this in ALSA?
>> 
>> I the meantime I finally figured out how this debug verb setting should work via:
>> 
>> # hda-verb /dev/snd/hwC0D0 0x14 0x70C 0
>> nid = 0x14, verb = 0x70c, param = 0x0
>> value = 0x0
>> # hda-verb /dev/snd/hwC0D0 0x15 0x70C 0
>> nid = 0x15, verb = 0x70c, param = 0x0
>> value = 0x0
>> 
>> which made no difference either, and the ALC889 spec reads “when pin
>> widget  SPDIF-IN is not connected via the programming configuration
>> register.”
>> 
>> Could that be a missing bit?
>> 
>> Any pointer or verbs I should poke welcome :-/
> 
> Well, from the codec POV, the SPDIF in is straightly connected from
> the pin to the audio in widget, so there should be no special thing
> there.  The possibly missing setup is the vendor-specific things, and
> Apple has been implementing the stuff always in a wild manner,
> e.g. doing via VREF, GPIO or whatever.

Did you check anything in this proc file codec setup I posted?

As far as I can see on schematics for the MacBook (e.g.. google returned
a APPLE_M42C_FA522_Macbook.pdf) the optical module RX output
seems to be “directly" attached to the codec’s spdif-in pin.

Yet on both, the MacBook as well on the MacBook Pro
I found no way to get any digital input captured. The same setup
works when booted in macOS, as well as when I plug
in my digital audio source into my aging maudio delta 1010,
with Linux, which, however, I do not want to continuously use for
this setup, …

It’s a pity, I don’t think there are so many other laptops with
optical input :-/

	René

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