Hello again,
as it is Sunday I thought it is a good time to further play with this annoying optical in issue. I plugged the fibre into a MacPro2,1 that we otherwise use as file server and such. Unfortunately ALSA indicates the same Realtek codec is used on it:
Chip: Realtek ALC889A
And, no surprise, capturing something on it:
arecord -D iec958 -f dat > rec.wav
yields nothing useful. Interestingly it yields not zeros, but another static pattern:
# hexdump -C rec.wav 00000000 52 49 46 46 24 00 00 80 57 41 56 45 66 6d 74 20 |RIFF$...WAVEfmt | 00000010 10 00 00 00 01 00 02 00 80 bb 00 00 00 ee 02 00 |................| 00000020 04 00 10 00 64 61 74 61 00 00 00 80 1b 08 1b 91 |....data........| 00000030 1b 08 1b 91 1b 08 1b 91 1b 08 1b 91 1b 08 1b 91 |................| * 00088020 1b 08 1b 91 1b 08 1b 91 1b 08 1b 91 |............| 0008802c
As I said before, according to the slightly mangled MacBook schematics the spdif pin at least on those looks directly connected with the optical receiver module.
Any tip of to debug this in the Linux driver would be welcome!
Also, I powered up the G5, to my surprise the ALSA sound-by-layout module does not even have spdif capture controls for that at all, (yes, the G5 also has optical in and out) … :-/
So in total about everything I could find around me has non working optical input with the ALSA drivers, …
René
On Apr 22, 2017, at 0:04, René Rebe rene@exactcode.de wrote:
Hi, On Apr 21, 2017, at 22:29, René Rebe rene@exactcode.de wrote:
Hi,
On Apr 21, 2017, at 20:01, Takashi Iwai tiwai@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@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 :-/
For the MacBook Pro I googled the i/o board schematics (820-2273 LIO.pdf) - unfortunately some lines are crippled / strange rectangles. However, it most likely spdif-in is directly connected like in the MacBook. The schematic calls the codec a ALC885 instead of the ALC889A as indicated by ALSA, … And the schematic labels the codec spdif innput pin SPDIFI/EAPD/MIDI-I/DMIC-R. However, the public ALC885 spec has a footnote “MIDI function is not supported as pins 46 and 48 are assigned as S/PDIF IO” and for the DMIC: “pin 47 can be configured to support a secondary digital mic input (DMIC-R). It is supported via a customized Realtek driver”
It is not getting better, …
:-/
-- ExactCODE GmbH, Lietzenburger Str. 42, DE-10789 Berlin http://exactcode.com | http://exactscan.com | http://ocrkit.com | http://t2-project.org | http://rene.rebe.de
Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel