Re: IRC: ALSA

[Thaddeus H. Black]

If ALSA sound does not interest you, neither will this post.  You can
skip it.

I wrote:
 [...]
 thb Sound problem.  On my system, /dev/dsp, /dev/midi and other sound
   devices seem to accept sound data as normal, but the speaker produces
   no sound.  My mixer is not zeroed.  I've ALSA and NAS installed, plus
   Esound and Jack because other packages depend on them.  If you have
   experience debugging Debian sound: where should I start looking for
   the solution, please?
 asg thb: does 'cat /dev/urandom  /dev/dsp' produce a horrible noise?
   silence? or an error?
 thb asg: thanks; stand by
 thb asg: I ran the command you suggested as root.  Silence, no error,
   no exit until I hit ^C.
 [...]
 Blissex thb: you may have one of those cards without mute/unmute then.
 thb Blissex: my sound chip is very common: AD1981, included on
   millions of recent Intel boards.  There is nothing unusual about it.
 Blissex thb: are you using the 'snd-intel8x0' driver though?
 thb Blissex: yes.  Hard-compiled into the kernel; not a module.
 Blissex thb: BTW ALSA should not be really compiled in the kernel,
   there may be problems if it is done like that.
 thb Blissex: wow!  That, I did not know.  Very good.
 Blissex thb: also have a look here: http://alsa.opensrc.org/intel8x0
   and the 8x0 subsection of http://tinyurl.com/4ogk2

For the record, Blissex' suggestion seems to have solved my problem.
ALSA had failed when recompiled monolithically into my 2.6.8 kernel; but
now that I configure ALSA as a set of modules and recompile the kernel
again, it seems to work fine.  If you encounter a similar problem---if
you have recompiled your 2.6 kernel monolithically and the snd_intel8x0
ALSA driver mysteriously produces no sound---try restoring
module-loading support, then recompile your kernel again with the ALSA
units as loadable modules.  Your kernel doesn't need any fancy automatic
module handling if you don't want it; basic CONFIG_MODULES and
CONFIG_MODULE_UNLOAD suffice.  See the Debian binary
package 'kernel-package' and the modprobe(8) manpage for further info.

How applicable the advice is to systems having non-intel8x0 sound chips
or running non-2.6 kernels, I admit that I do not know; Debian sound is
not my area of expertise and I don't know much about it.  This post is
to report for the list archive what happened to work for me.  For the
benefit of confused Debian beginners who may stumble upon this post,
however, I should observe that unless you have deliberately recompiled
your kernel (this does not happen by accident; if you had done it, you
would know), the advice probably does not pertain to you.

(It may not matter, but to complete the technical report: my specific
motherboard is the Intel D845GEBV2L.  This motherboard provides sound
through an onboard Analog Devices AD1981 chip, which is one of the
several chips the snd_intel8x0 ALSA driver drives.  The reference OS is
Debian 3.1r0a sarge stable.)

I am not subscribed to debian-user, so please e-mail me directly if you
want to reach me over this.

-- 
Thaddeus H. Black
508 Nellie's Cave Road
Blacksburg, Virginia 24060, USA
+1 540 961 0920, [EMAIL PROTECTED], [EMAIL PROTECTED]


signature.asc
Description: Digital signature

IRC: ALSA

[Thaddeus H. Black]

Some people on the #debian IRC channel gave me some useful advice
regarding Debian, sound and ALSA yesterday.  It seems unlikely that the
advice is useful just to me.  If it is good to post the advice where
others can search it out later, then the relevant log extract follows.

Keywords: Debian, sound, ALSA, OSS, NAS, mixer, amixer, scontrols, dsp,
kernel, module, Intel, AD1981.

#debianthb   H   (Thaddeus H. Black)
#debianBlissex   H   (http://WWW.sabi.co.UK/)
#debianasg   H   (Adam Garside)
#debianNiki  H   [/whois not captured]
#debian[nick1]   H   [actual nick unprintable]
thb Sound problem.  On my system, /dev/dsp, /dev/midi and other sound
  devices seem to accept sound data as normal, but the speaker produces
  no sound.  My mixer is not zeroed.  I've ALSA and NAS installed, plus
  Esound and Jack because other packages depend on them.  If you have
  experience debugging Debian sound: where should I start looking for
  the solution, please?
asg thb: does 'cat /dev/urandom  /dev/dsp' produce a horrible noise?
  silence? or an error?
thb asg: thanks; stand by
thb asg: I ran the command you suggested as root.  Silence, no error,
  no exit until I hit ^C.
asg thb: okay, then your mixer may be mutted irrespective of the
  levels
asg thb: or your speakers are not plugged in or wired properly.
Blissex thb: read carefully the troubleshooting, OSS comaptibility and
  app config sections of http://tinyurl.com/4ogk2
thb asg: Okay.  I'll go chew on that for a while.
thb Blissex: thank you.  I will do it.
[nick1] Blissex, you wrote this conf?
Blissex [nick1]: yes, I did. More or less precisely for people like
  your and thb.
Niki thb: Please run: amixer set 'Master' 'unmute' '100' and  amixer
  set 'PCM' 'unmute' '100', the try again.
thb Niki: understood; stand by.
thb Niki: error message: amixer: Unknown playback setup 'unmute'..
Blissex thb: swap around the 100 and unmute.
thb Blissex, Niki, asg: same error message after swapping.  All right.
  Something is evidently set up wrong on my system, but you have given
  me some good ideas where to start looking for the solution.  With
  these new clues, I should go away for a while now and work on the
  problem some more.  Thank you.  I may return with further questions
  later.
asg thb: good luck on getting things working
Niki thb: Goog luck!
Blissex thb: try this more precisely:
Blissex thb: amixer sset Master 80% unmute
Blissex thb: some cards however do not need to have controls unmuted,
  so if that the case, remove the unmute.
thb Blissex: Hrm.  Same error msg: amixer: Unknown playback setup
  'unmute'..
Blissex thb: to see what you can set or not, 'amixer' or 'amixer
  scontrols' or 'amixer scontents'
Blissex thb: [nick1]: BTW, usually you should ask sound questions in
  #ALSA
thb Blissex: didn't know about #ALSA; now I know.  To answer the
  question about amixer scontrols, it replies normally: it lists five
  simple mixer controls: Master, Synth, Line, CD, Mic.
Blissex thb: you may have one of those cards without mute/unmute then.
thb Blissex: my sound chip is very common: AD1981, included on
  millions of recent Intel boards.  There is nothing unusual about it.
Blissex thb: are you using the 'snd-intel8x0' driver though?
thb Blissex: yes.  Hard-compiled into the kernel; not a module.
Blissex thb: BTW ALSA should not be really compiled in the kernel,
  there may be problems if it is done like that.
thb Blissex: wow!  That, I did not know.  Very good.
Blissex thb: also have a look here: http://alsa.opensrc.org/intel8x0
  and the 8x0 subsection of http://tinyurl.com/4ogk2

I am not subscribed to debian-user, so please e-mail me directly if you
want to reach me over this.


signature.asc
Description: Digital signature