Re: [OSS] Add CXT48 to modem black list in ac97

SuD (Alex)
2005-04-13T21:59:39Z

Herbert Xu wrote:

>BTW Alex, if you have the time please determine whether ALSA
>works properly on your machine.
>
>
Yes, alsa works, it's what i'm using now.

About how alsa detects the hardware, i have been reading some sources
and didn't get the whole point, but some facts:
- In intel8x0.c:
In snd_intel8x0_probe() there is a call to snd_intel8x0_mixer().
In that function it does: ac97.scaps = AC97_SCAP_SKIP_MODEM;

- In intel8x0.c:
In snd_intel8x0m_probe() there is a call to snd_intel8x0_mixer().
In that function it does: ac97.scaps = AC97_SCAP_SKIP_AUDIO;

- After that is done, in ac97_codec.c:
http://lxr.linux.no/source/sound/pci/ac97/ac97_codec.c#L1921
It checks for _SKIP_ variables and probes for soundcard (checking a
mixer register) and modem (checking modem_id).

As a result, if i insert "snd-intel8x0" it will detect a soundcard (pci
0:0:1f.5), but if insert instead
"snd-intel8x0M" it will detect a modem (pci 0:0:1f.6).
If a modem is detected i get errors like: "MC'97 0 converters and GPIO
not ready (0x1)", and not sure how to test it.
If i load both modules only the first will work. The second will give an
probe error -13 (EACCES?), because it has been marked as audio device,
but also marked as _SKIP_AUDIO (ac97_codec.c:1862), or viceversa.

PS: And i finally subscribed to the list, thanks for your patience.