I like to use the optical IEC958 (toslink) output of my motherboard for sound.
This works great from the console before starting X.

When I log in to KDE I hear the welcome music but no other application produces sound. When I log out of KDE I hear the logout sound.

I have deleted .kde4

KDE 4.6.4 on Gentoo kernel 2.6.39 Nvidia Intel HDA with AD1988 codec

There is a Multimedia System notification "The audio playback device hw:0,1 does not work. Falling back to hw:0,1"

This notification is obviously wrong as I can hear the login and logout sounds.

The analogue o/p works o.k. when selected.

The digital channel worked o.k. until a recent KDE update (can't remember which one).

Anybody else seen this?

Many thanks

Do you have Pulseaudio installed on your system, or any other application which would lock the audio device or otherwise interfere with DMix?

No extras, a simple install. No HAL if that matters.

Thanks for your time.

I should say I also hear KDE notifications and being in the audio group makes no odds. Clementine does not work.

Someone on the Gentoo forums had same problem, and disabled KDE notifications audio. This solved the problem. Looks like a KDE bug. I won't put solved in title as a bit of a fudge.

Please post the results of "lsof | grep /dev/snd" to see if any application is squatting on the digital audio device.

Also, is the digital output shown in the output of "aplay -l"?

Hi,
I have exactly the same problem (gentoo up to date, kde 4.6.5)...
aplay -l shows the digital output and lsof | grep /dev/snd gives
kded4 8178 bruno 24u CHR 116,5 0t0 180 /dev/snd/controlC0
knotify4 8205 bruno mem CHR 116,2 176 /dev/snd/pcmC0D1p
knotify4 8205 bruno 20u CHR 116,2 0t0 176 /dev/snd/pcmC0D1p
kmix 8304 bruno 12u CHR 116,5 0t0 180 /dev/snd/controlC0

killing knotify4 resolves the problem !

**** List of PLAYBACK Hardware Devices ****
card 0: CMI8768 [C-Media CMI8768], device 0: CMI8738-MC8 [C-Media PCI DAC/ADC]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: CMI8768 [C-Media CMI8768], device 1: CMI8738-MC8 [C-Media PCI 2nd DAC]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: CMI8768 [C-Media CMI8768], device 2: CMI8738-MC8 [C-Media PCI IEC958]
Subdevices: 1/1
Subdevice #0: subdevice #0

I have the same problem with no optical output. I seem to remember turning off the analogue forces a digital output from device 2, but it doesn't work any more.
Help with diagnosing this would be much appreciated.

my issue is now SOLVED. I consoled alsamixer and used M to turn on the spdif output.