Re: [alsa-devel] Bugs on aspire one A150

[Takashi Iwai <tiwai@suse.de>]

At Tue, 17 Mar 2009 11:47:55 +0100,
Andreas Mohr wrote:
> 
> On Tue, Mar 17, 2009 at 11:38:45AM +0100, Andreas Mohr wrote:
> > NOPE. Aspire One most definitely has a Fortemedia SAM (small array
> > microphone) due to this output:
> > http://sites.google.com/site/kengell/acer-aspire-one---dmesg
> > 
> > "
> > ...
> > ForteMedia SAM-Soft Library Loaded!
> > 
> > ALC INIT
> > ...
> > "
> > 
> > I had already wanted to add the mention of Fortemedia as microphone
> > manufacturer (forgot this last time), then I researched more and found it.
> > 
> > Fortemedia device names include FM2018-380, not sure yet which one is in
> > Aspire One.
> > 
> > http://www.fortemedia.com/products/index.htm
> > ( especially http://www.fortemedia.com/products/fm1182.htm )
> 
> http://www.wpgholdings.com/event/S/SACg_04_ForteMedia_SAM.pdf
> mentions "FM201x" and www.sacg.com.tw (this one could be useful!).
> Searching Google "FM201[0-9] Fortemedia" comes up with FM2010 and
> FM2018 and thus
> http://www.hengdasheng.com.cn/uploadfile/391/cfile/2008102414057847.pdf
> which is a relatively informative datasheet.

I'm not sure whether FM2018 is on a netbook.  Rather my guess is it's
a digital-mic component by FortMedia together with their software
library for SAM handling.


BTW, a simple "fix" for the mono capture problem, you can patch
the config file for HD-audio in alsa-lib like below.  Then the first
channel will be used for mono capture instead of averages.
Give it a try.

(But, this won't fix programs that prefer "hw" access such as
 pulseaudio, of course.)


Takashi

---
diff --git a/src/conf/cards/HDA-Intel.conf b/src/conf/cards/HDA-Intel.conf
index 800281e..d3ac002 100644
--- a/src/conf/cards/HDA-Intel.conf
+++ b/src/conf/cards/HDA-Intel.conf
@@ -57,6 +57,8 @@ HDA-Intel.pcm.default {
 			max_dB 30.0
 			resolution 121
 		}
+		# to avoid possible phase inversions with digital mics
+		route_policy copy
 	}
 	hint.device 0
 }