the State of Linux Audio
I'm the one who has been asking questions about getting an
old Dell Dimension mother board with an on-board CS4236 sound
card to work again after upgrading to wheezy.
For years, I have had pulseaudio and alsa on this system
and have also seen what I will describe as weirdness which makes
me wonder what is really working and what is not. If you do
ps ax |grep pulseaudio |grep -v grep
to look for any pulseaudio processes, one does find a process
for pulseaudio and it is configured for per-user sessions.
You can reportedly play multiple audio sources with
pulseaudio but I have never been able to play more than one
source at a time with further attempts to play something
resulting in a "device busy" error which is normally not a
problem but it's obviously not coming from pulseaudio.
This system also has no X-windows clients and thus is a
command-line-only system but I constantly see the following
message in syslog:
wb5agz pulseaudio[20877]: [pulseaudio] server-lookup.c:
Unable to contact D-Bus: org.freedesktop.DBus.Error.Not Supported: Unable
to autolaunch a dbus-daemon without a $DISPLAY for X11
This looks pretty sick to me but it could be that the
daemon is working but just can't shout out to anyone which is
kind of dumb since an error message looks just as informative on
a console as it does in a GUI.
The only reason I put pulseaudio on here was way back
when I was running lenny and had no /dev/dsp. Someone suggested
installing pulseaudio. I did. /dev/dsp came back and life
marched on.
Generally, sound got easier and better with upgrades but
the upgrade to wheezy turned back the clock and sound is broken
for all practical purposes. There were actually two sound
cards, the CS4236 on the mother board plus an AWE64 Gold which
behaves like a SBLive board in Linux. No wave tables or other
special effects but recording and playback are fine.
After the wheezy upgrade, both sound cards went poof and
one would never know they were there except the CS4236 shows up
in dmesg as a plug-and-play card. The SBLive does a better job
of hiding but manages to sometimes be able to kill the Ethernet
interface probably by fighting over the same interrupt.
a Soundblaster Digi which is a fancy USB card that had worked
fairly well both recording and playing under squeeze now limps
along with only playback of the left and right channels and
absolutely nothing else.
Nothing regarding sound is better on this system and
many things that have worked flawlessly for over ten years such
as the ability to autodetect the on-board sound card and install
a /dev/dsp device are all gone.
I have an ace in the hole in that I had an extra boot
drive so I used dd to copy the original squeeze drive to the new
soon-to-be wheezy drive. After running the upgrade and loosing
all the sound, I can simply slip the squeeze drive back in and
there should be music again but support for squeeze is running
out soon and, as a retired worker in network operations, I know
that one of the best ways to be safe on the internet is to keep
your computer's OS up to date. The rifraf out there will at
least have a little more trouble cracking your system if it is
current than they will if it is several revisions behind and
all the bad guys know how to break in.
Except for the sound, everything else seems to be in
order though it is, of course, hard to tell for sure until you
try to do something and now you can't when you could before the
upgrade.
Legacy code is not necessarily bad and one would hope
that new code builds on the legacy as opposed to just whacking
off stuff that used to work and replacing it with something that
instantly renders a whole table full of equipment useless. One
expects things like that from purely commercial software but one
of the neat things about Linux is that it isn't or at least
wasn't quite as picky about hardware.
Oh well, I am dangerously close to ranting so let's stop
and see what others say.
Mainly, if there is a better way to do Linux sound, I'm
all ears. The silence is deafening.
Martin McCormick
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