[alsa-devel] Got microphone working with SigmaTel STAC 9221 A1 on a Dell XPS M1210

Takashi Iwai tiwai at suse.de
Tue Jun 12 15:19:02 CEST 2007

At Sat, 09 Jun 2007 16:37:11 -0700,
Eran Guendelman wrote:
> I installed SuSE 10.2 on my new XPS M1210 laptop and found that the 
> microphone was not working (headphones and internal speakers worked 
> fine).  I eventually got it working, and wanted to write an email 
> describing how I did this.
> The two main important steps (which I will describe in more detail 
> below) were:
> - Changing the default pin configurations ref922x_pin_configs in 
> patch_sigmatel.c to values that were based on the windows driver's INI 
> file but with one important tweak.
> - Running the driver using the "model=ref" parameter so that the above 
> modified pin configurations are used.
> Note that it could be that my solution is overkill and there's actually 
> a way to get this working with the unmodified alsa drivers...  But I did 
> not find any such solutions (e.g. I've tried setting "model=ref", 
> "model=3stack", "model=5stack", but none of those fixed the microphone). 

So, we need to add a new model.  Could you give the output of "lspci
-nv", too?  We need PCI SSID to identify the device.  Then I can write
a patch to try.

> - Why does patch_sigmatel.c "fix" mux capture levels to 2?  The Mux 
> (0x12) ends up in the path from the mic in jack to the audio in, so is 
> it supposed to act as a Mic Boost or something?

The debug with intel macs revealed that a too high mux capture value
results in disablement of the recording functionality.  Thus, it's now
limited to 2, the highest value it accepted.

> - I noticed my headphone jacks (0x0a, 0x0f) have Pin-ctls set at 0xc0 
> which is OUT HP (i.e. uses a low impedance amplifier for headphone 
> output).  Would it damage my sound card or speakers if I connected these 
> jacks to powered speakers or to an audio receiver (i.e. more 
> traditionally connected to a Line Out)?

Practically, I don't think so.  This setup is normal over all

> - Does the snd_hda_intel driver currently (or will it eventually) 
> support dynamic switching so I can switch from the Mic In to Line In or 
> to Rear Speakers Out, etc, just like in the Windows driver?

Hm?  It should have already the switches, "Line In As Output" and "Mic
As Output"...

> - Some solutions on the internet talked about creating an .asoundrc file 
> to get the codec working...  I don't understand what that file is for 
> and whether I need to tweak it at all...  But since I have a working 
> solution without the file I guess I'm fine?

A rumor is a rumor.  asoundrc has nothing to do with the codec :)



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