[alsa-devel] SPDIF/IEC958 sample rate on HDA/ALC882

[Dominique Dumont]

Dag Lem <dag at nimrod.no> writes:

>
> Since I can't find any obvious mistake in the HDA code, I guess there is some
> problem in patch_realtek.c, or an initialization incompatibility with the HDA
> code and the ALC882 chip.
>
> There are certainly initialization problems somewhere, as the S/PDIF output is
> sometimes not able to send AC3 data correctly (amplifier cannot detect AC3 and
> stays silent), and  attempting to play audio (even 48kHz) results in
> intermittent screeches. This is solved by setting and resetting the IEC958
> control widget, trying again and again until it finally works. When it does
> work, it works without a hitch until the next reboot.
>
> Any ideas? Is there anything I can help to test in order to nail down the
> problem? My motherboard is an Asus P5W DH Deluxe with an 82801G HDA controller,
> in case this has any relevance.

I'm looking at a same kind of issue for my MSI mobo (ALC883).

There's something fishy about the verb used to set the stream format
(also referred as stream converter in realtek's doc).

The verb used in snd-hda-intel are 0x200 and 0x300 where Intel's and
Realtek's doc specify 2h and 3h.

So I tried to switch the verbs to 0x002 and 0x003, but it did not
work. :-( (it would be too easy ;-) )

The parameter passed with these verbs also look fishy, but I
can't say more as I was to tired to dig further. I'll have a look
tonight.

HTH