alsamixer/sound suddenly only work as root in Fedora Core 5?

anvilravine · 08-29-2008, 04:45 PM

Hi all. I'm having a problem with my soundcard (Turtle Beach Montego) running under Fedora Core 5. I use this box as a jukebox/media player hooked up to the living area stereo, and it has worked just fine for the last 2-3 years.

Now suddenly there are problems that seem to reoccur after rebooting and I'm not sure what is changing. I cannot run the 'alsamixer' program as any user other than root.

Code:

~ $ alsamixer

alsamixer: function snd_ctl_open failed for default: No such device

A friend fixed this once before and tells me it is a permissions problem with the audio hardware, but I don't know how to fix it, or why it keeps coming back. What device(s) do I have to chmod and to what should I change the permissions?

Also, mplayer from the command line refuses to playback audio as anyone other than root. It says it is playing but no audio comes out (sent to a null audio device maybe?):

Code:

$  mplayer standardtuning.mp3
MPlayer 1.0rc1-4.1.1 (C) 2000-2006 MPlayer Team
CPU: Intel Celeron 2/Pentium III Coppermine,Geyserville (Family: 6, Model: 8, Stepping: 3)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 0

Playing standardtuning.mp3.
Audio file file format detected.
==========================================================================
Opening audio decoder: [mp3lib] MPEG layer-2, layer-3
AUDIO: 22050 Hz, 2 ch, s16le, 64.0 kbit/9.07% (ratio: 8000->88200)
Selected audio codec: [mp3] afm: mp3lib (mp3lib MPEG layer-2, layer-3)
==========================================================================
[AO OSS] audio_setup: Can't open audio device /dev/dsp: Permission denied
alsa-lib: confmisc.c:848:(snd_func_card_driver) cannot find card '0'
alsa-lib: conf.c:3500:(_snd_config_evaluate) function snd_func_card_driver returned error: No such device
alsa-lib: confmisc.c:397:(snd_func_concat) error evaluating strings
alsa-lib: conf.c:3500:(_snd_config_evaluate) function snd_func_concat returned error: No such device
alsa-lib: confmisc.c:1248:(snd_func_refer) error evaluating name
alsa-lib: conf.c:3500:(_snd_config_evaluate) function snd_func_refer returned error: No such device
alsa-lib: conf.c:3972:(snd_config_expand) Evaluate error: No such device
alsa-lib: pcm.c:2145:(snd_pcm_open_noupdate) Unknown PCM default
alsa-init: playback open error: No such device
[AO ARTS] can't connect to aRts soundserver
ALSA lib confmisc.c:848:(snd_func_card_driver) cannot find card '0'
ALSA lib conf.c:3500:(_snd_config_evaluate) function snd_func_card_driver returned error: No such device
ALSA lib confmisc.c:397:(snd_func_concat) error evaluating strings
ALSA lib conf.c:3500:(_snd_config_evaluate) function snd_func_concat returned error: No such device
ALSA lib confmisc.c:1248:(snd_func_refer) error evaluating name
ALSA lib conf.c:3500:(_snd_config_evaluate) function snd_func_refer returned error: No such device
ALSA lib conf.c:3972:(snd_config_expand) Evaluate error: No such device
ALSA lib pcm.c:2145:(snd_pcm_open_noupdate) Unknown PCM default
[AO ESD] esd_open_sound failed: Connection refused
ao_nas: init(): AUDIOSERVER environment variable not set -> nosound
[AO SDL] Samplerate: 22050Hz Channels: Stereo Format s16le
alsa-lib: confmisc.c:848:(snd_func_card_driver) cannot find card '0'
alsa-lib: conf.c:3500:(_snd_config_evaluate) function snd_func_card_driver returned error: No such device
alsa-lib: confmisc.c:397:(snd_func_concat) error evaluating strings
alsa-lib: conf.c:3500:(_snd_config_evaluate) function snd_func_concat returned error: No such device
alsa-lib: confmisc.c:1248:(snd_func_refer) error evaluating name
alsa-lib: conf.c:3500:(_snd_config_evaluate) function snd_func_refer returned error: No such device
alsa-lib: conf.c:3972:(snd_config_expand) Evaluate error: No such device
alsa-lib: pcm.c:2145:(snd_pcm_open_noupdate) Unknown PCM default
ALSA lib confmisc.c:848:(snd_func_card_driver) cannot find card '0'
ALSA lib conf.c:3500:(_snd_config_evaluate) function snd_func_card_driver returned error: No such device
ALSA lib confmisc.c:397:(snd_func_concat) error evaluating strings
ALSA lib conf.c:3500:(_snd_config_evaluate) function snd_func_concat returned error: No such device
ALSA lib confmisc.c:1248:(snd_func_refer) error evaluating name
ALSA lib conf.c:3500:(_snd_config_evaluate) function snd_func_refer returned error: No such device
ALSA lib conf.c:3972:(snd_config_expand) Evaluate error: No such device
ALSA lib pcm.c:2145:(snd_pcm_open_noupdate) Unknown PCM default
[AO SDL] Unable to open audio: No available audio device
Opening /dev/dvb/adapter0/audio0
DVB AUDIO DEVICE: No such file or directory
AO: [null] 22050Hz 2ch s16le (2 bytes per sample)
Video: no video
Starting playback...
A:   6.4 (06.3) of 32.0 (32.0)  1.3%
Exiting... (Quit)

I'd really like to know what is causing this. Help is much appreciated. If you need the output of anything please let me know. Thank you.

pinniped · 08-29-2008, 07:09 PM

1. check the owner/permissions on the audio device:
ls -l /dev/snd/

2. If the 'group' is 'audio' or similar and has r/w permission, then you need to add your users to that group. If the group is 'root', you probably need to edit the udev rules. The udev rules are in /etc/udev/rules.d (although some may also be stuffed in /etc/udev) You can read through the rules to see if any deal with your sound card.

To make up your own rules, find out how to uniquely identify a device - for example:
cd /sys/class/sound
udevinfo -a -p ${PWD}/controlC0

looking at device '/class/sound/controlC0':
KERNEL=="controlC0"
SUBSYSTEM=="sound"
DRIVER==""
ATTR{dev}=="116:0"

Now I can write a rule for that particular class of device:
KERNEL=="controlC*", GROUP="audio", MODE=0660

anvilravine · 08-30-2008, 12:29 AM

I'm following along as best I can and I think I get the gist of what you're saying, but let me make sure.

Code:

# ls -l /dev/snd
total 0
crw------- 1 root root 116, 10 Aug 28 22:24 controlC0
crw------- 1 root root 116,  4 Aug 28 22:24 midiC0D0
crw------- 1 root root 116,  9 Aug 28 22:24 pcmC0D0c
crw------- 1 root root 116,  8 Aug 28 22:24 pcmC0D0p
crw------- 1 root root 116,  7 Aug 28 22:24 pcmC0D1p
crw------- 1 root root 116,  6 Aug 28 22:24 pcmC0D2p
crw------- 1 root root 116,  5 Aug 28 22:24 pcmC0D3p
crw------- 1 root root 116,  3 Aug 28 22:24 seq
crw------- 1 root root 116,  2 Aug 28 22:24 timer

If I'm interpreting this correctly, on my system only root has r/w access to any of the sound devices, and no one else can do so much as touch them. All the sound devices are owned by root and are in the group 'root', which means I need to check &/or edit the udev rules. Okay...

Code:

# ls /etc/udev/rules.d
05-udev-early.rules  51-hotplug.rules  60-pcmcia.rules       alsa.rules
10-wacom.rules       60-libsane.rules  90-hal.rules
50-udev.rules        60-net.rules      95-pam-console.rules

Do I need to be looking at "50-udev.rules", "alsa.rules" or something else? I am assuming "50-udev-rules". In that config file:

Code:

# There are a number of modifiers that are allowed to be used in some of the
# fields.  See the udev man page for a full description of them.
#
# default is OWNER="root" GROUP="root", MODE="0600"
#

KERNEL=="*", OWNER="root" GROUP="root", MODE="0600"

So are you saying I need to add something like

Code:

KERNEL=="controlC*", GROUP="audio", MODE="0660"

to /etc/udev/rules.d/50-udev-rules ?