[ydl-gen] Sound on G4 PowerMac (digital audio)

[Derick Centeno]

On Thu, 1 Jul 2010 09:30:39 +1000
Stephen Harker <sjh at adfa.edu.au> wrote:

> On Wed, Jun 30, 2010 at 11:52:41AM -0400, Derick Centeno wrote:
> > On Wed, 30 Jun 2010 07:35:19 -0600
> > Thomas Carlson <tcarlson at sharedcup.com> wrote:
> > 
> > > Derick:
> > > 
> > > I did what you suggested:  changed my window manager to xfce (very
> > > nice, I'm keeping it) and went to Settings/Settings Manager/Sound.
> > > All the controls are at 0 which tells me that the default setting
> > > is not recognizing the sound card.  In the Volume Control utility
> > > I can't get it to go from headphone to PC speaker.  I had the same
> > > problem with a Debian installation a while back.  Maybe PowerMac
> > > G4 (Digital Audio) is an oddball among the other PM G4s.
> > > 
> > > Thanks for the response, though.
> > > 
> > > Tom
> > 
> > Try this Tom:
> > 
> > >From anywhere within the xfce desktop right-click and then select
> > Settings --> Mixer Settings.  This dialog, simply called sound, is
> > more specific in controlling the hardware; on my system there are
> > two options default and something called PowerMac Snapper.  PowerMac
> > Snapper works for me, if you've a different card it should show up
> > there.
> 
> One question, should this powermac G4 be using the snd-aoa driver
> (http://alsa.opensrc.org/index.php/Aoa> rather than snd-powermac
> <http://alsa.opensrc.org/index.php/Powermac>?  I don't know what the
> correct module is for the model listed.
> 
> With my iBook G4 1.33MHz 12inch I found that snd-powermac did not
> work.  To get snd-aoa to work I had to compile a kernel without
> snd-powermac but with snd-aoa.  If I had both lsmod would always list
> snd-powermac as would the system-config-soundcard utility and sound
> would not work.  After compiling the new kernel sound works and I
> have:
> 
> # cat /proc/asound/cards
>  0 [SoundByLayout  ]: AppleOnbdAudio - SoundByLayout
>                       SoundByLayout
> 
> # lsmod | grep snd
> snd_aoa_codec_tas      10697  2 
> snd_aoa_fabric_layout   9534  0 
> snd_aoa_i2sbus         18011  1 
>...

Hi Stephen:

Within XFCE there is an app accessible by going to the XFCE menu or by
right-clicking on a three-button mouse: Other --> Soundcard Detection.
After entering the root password for your system which you created when
you first installed YDL (hopefully you created a separate root password
and user password at that time) the Soundcard Detection app will come
up (it shows up with the name Audio configuration) and you'll notice
three tabs one of which is called System click that one.  You'll see an
option for a Report.  If you click on that button a file will be
placed in the root directory with the name: scsconfig.log.  It can be
opened with vim or any other text editor of your choice.

This report collects all elements for you regarding the sound device
you have installed.  What is useful about it is that different sections
list the commands used to generate the data below it.  This can be a
time saver when one is looking to resolve a problem.

I'm going to utilize commands utilized in generating different sections
of that report to address what you posted.  The entire report is over
1000 lines and although a good source of study; surpasses the intent of
the current discussion.

[root at arakus ~]# lsmod|grep snd
snd_aoa_i2sbus         20296  0 
snd_powermac           46944  1 
snd_seq_oss            35724  0 
snd_seq_midi_event      6488  1 snd_seq_oss
snd_seq                59268  4 snd_seq_oss,snd_seq_midi_event
snd_seq_device          6824  2 snd_seq_oss,snd_seq
snd_pcm_oss            43520  0 
snd_mixer_oss          16160  1 snd_pcm_oss
snd_pcm                77528  3 snd_aoa_i2sbus,snd_powermac,snd_pcm_oss
snd_timer              22016  2 snd_seq,snd_pcm
snd_page_alloc          8672  1 snd_pcm
snd                    53520  11
snd_aoa_i2sbus,snd_powermac,snd_seq_oss,snd_seq,snd_seq_device,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_timer
soundcore               6300  1 snd snd_aoa_soundbus        4872  1
snd_aoa_i2sbus

Something should strike you immediately.  You have the snd_aoa_i2sbus
module; I instead have snd_powermac.  The calls by modules, made
available by software libraries, to the sound device must be adapted to
utilize the hardware devices we actually have installed.  This takes a
bit of research as you did. If you look closely, you'll notice that
snd_powermac and snd_aoa_i2sbus modules can act on other modules as
alternatives to one another in certain instances.  

If you explore (open modprobe.conf with vim) /etc/modprobe.conf  on my
system here is what would be there:

alias eth0 sungem
alias snd-card-0 snd-powermac
options snd-card-0 index=0
options snd-powermac index=0

Yours could be different.

Also if you did the following command on my system, you'll see what
hardware I have installed:

# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Snapper [PowerMac Snapper], device 0: PMac Snapper [PowerMac Snapper]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
#

Yours may be different.

Final note:  I've found it useful that when I'm in user mode ($) and
want to move into root to execute a command instead of using sudo I do
the following:

$ su -
#

The difference is that this allows you to have any Linux, behave as
though all Linux commands were available regardless what directory you
are invoking those commands from or where the commands actually are
within the Linux directory tree.

All the best...