[alsa-devel] Problems with ALC882

Christophe Osuna christophe.osuna at gmail.com
Mon Jan 21 12:27:18 CET 2008

Tobin, thanks for all the information you provided.

2008/1/18, Tobin Davis <tdavis at dsl-only.net>:
>   Yes, it "should".  But it also depends on the physical wiring of your system.  If you have a system with only 3 audio jacks in the back, it is very difficult to have surround sound & 3 inputs at the same time.

I have plenty of jacks, including one "Mic", one "Front Mic" and one "Line In".

2008/1/18, Takashi Iwai <tiwai at suse.de>:
> Just deeper looking at the code, I found it's indeed buggy for the
> secondary ADCs.  The patch below should fix it.
> The second and third ADCs are assigned to PCM#2 while the first ADC is
> to PCM#0.  This is for avoiding the confusion of dsnoop and
> multi-streams.
> Give it a try and check whether it doesn't break, at least, for
> recording the first ADC.  If it's OK, I'll apply it to the HG tree
> later.

Thanks for the patch. Applying it did seem to solve the problem; now I
can use the three ADC that are mapped to hw:0,0,0 hw:0,2,0 and
hw:0,2,1. I have successfully tested the following commands

  arecord -f dat -D hw:0,0,0 | aplay -f dat -D hw:0,0,0
  arecord -f dat -D hw:0,2,0 | aplay -f dat -D hw:0,0,0
  arecord -f dat -D hw:0,2,1 | aplay -f dat -D hw:0,0,0

It wasn't necessary to override the "substream" value in
"alc880_pcm_analog_alt_capture" (I suppose that both analog_capture
and analog_alt_capture are used). Now I need to check that I can open
the three at the same time but I am rather confident on this.

Could you also tell me where I have to change code in order to force
the 8 kHz sampling rate? I will try to add an ugly change to
snd_hda_query_supported_pcm() but I am not sure on whether this is the
right place.

More information about the Alsa-devel mailing list