No sound on IEC958 (S/PDIF) output after switching user

[Gert van Dijk]

I have found a (sometimes) reproducible path to render the digital output of my soundcard useless, until reboot.

1. Log in as user A
2. Select "Digital Stereo (IEC958) Output + Analogue Stereo Input" in the Sound Preferences for the sound card.
3. Play some audio, this works fine over the digital output.
4. Log out and log in as user B with the preference of "Analog Stereo Duplex"
5. Play some audio, this works fine over the analogue output.
6. Log out and log back in as user A.
7. Try to play some audio over the still selected digital output. This doesn't work. Pulseaudio seems to be unable to open the right Alsa resources (see my pulseaudio debug log attached - see the remarks below).
8. Selecting other output methods won't help, restarting Pulseaudio doesn't make a difference.

Notes:
- Other paths may be valid too, I experience it also when switching between audio applications.
- All information for this bug report was gathered after step 8.
- I've disabled all sound for GDM (see below).

This seems to be reproducible for about 50% of the times and also occurs sometimes when GDM is using the analogue output on the login screen, then switching to digital output after logging in. After I disabled the sounds for the GDM greeter, it saved me a lot of reboots to get sound even right after a cold boot.

Of course, I've checked all alsa mixers (alsamixer from terminal). Also I've tried the natty-proposed kernels -9 and -10 as well as the stock -8.

The Alsa driver seems to be locked up somewhere. A reboot of my machine always resolves the lock up and everything works fine again.
From the Pulse verbose log I see the following interesting line a lot of times appearing:
I: (alsa-lib)pcm_hw.c: open '/dev/snd/pcmC1D0p' failed (-2)
I: alsa-util.c: Failed to set hardware parameters on plug:iec958:1: Invalid argument
I: alsa-util.c: Failed to set hardware parameters on plug:hw:0: Invalid argument
During the capture of this log, I was trying to get sound on my digital output, but I failed. I got sound after I switched to analogue output. My A/V receiver which is connected to my notebook didn't respond at all, not even a type of signal (PCM, AC-3, etc.) was displayed.

This particular issue has never occured to me on Ubuntu versions 8.04, 8.10, 9.04, 9.10 and 10.10. The hardware: a Thinkpad T61p notebook with an Intel HDA onboard soundcard.

Please let me know on how to debug this issue better.

Other output:

$ iecset
Mode: consumer
Data: audio
Rate: 48000 Hz
Copyright: permitted
Emphasis: none
Category: PCM coder
Original: original
Clock: 1000 ppm

Disabling pulseaudio, then
$ aplay -D plug:iec958 /usr/share/sounds/alsa/Front_Center.wav
gives nothing, should be digital output.
$ aplay -D plug:front /usr/share/sounds/alsa/Front_Center.wav
works, analogue output.

$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Intel [HDA Intel], device 0: AD198x Analog [AD198x Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 1: AD198x Digital [AD198x Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

$ getent group | grep audio
audio:x:29:pulse

No users have any specific alsa configuration, nor is there any /etc/asound.conf file present.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: alsa-base 1.0.24+dfsg-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-10.44-generic 2.6.38.7
Uname: Linux 2.6.38-10-generic x86_64
NonfreeKernelModules: nvidia
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: gert 20527 F.... alsamixer
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xfe220000 irq 49'
   Mixer name : 'Analog Devices AD1984'
   Components : 'HDA:11d41984,17aa20bb,00100400'
   Controls : 31
   Simple ctrls : 19
Card1.Amixer.info:
 Card hw:1 'Camera'/'Camera at usb-0000:00:1a.1-1, full speed'
   Mixer name : 'USB Mixer'
   Components : 'USB046d:08f5'
   Controls : 3
   Simple ctrls : 2
Card29.Amixer.info:
 Card hw:29 'ThinkPadEC'/'ThinkPad Console Audio Control at EC reg 0x30, fw 7KHT24WW-1.08'
   Mixer name : 'ThinkPad EC 7KHT24WW-1.08'
   Components : ''
   Controls : 1
   Simple ctrls : 1
Card29.Amixer.values:
 Simple mixer control 'Console',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [on]
Date: Wed Jun 8 00:13:15 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110426)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_GB:en
 LANG=nl_NL.utf8
 LC_MESSAGES=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: alsa-driver
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/25/2008
dmi.bios.vendor: LENOVO
dmi.bios.version: 7LETB7WW (2.17 )
dmi.board.name: 6457WY9
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr7LETB7WW(2.17):bd04/25/2008:svnLENOVO:pn6457WY9:pvrThinkPadT61p:rvnLENOVO:rn6457WY9:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 6457WY9
dmi.product.version: ThinkPad T61p
dmi.sys.vendor: LENOVO

[Rolf Leggewie (r0lf)]

does this ever occur in precise or later?

[Rolf Leggewie (r0lf)]

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to "New". Thanks again!