Comment 38 for bug 1498129

Raymond - thank you for all your help. I now have my Xonar U7 Echelon Ed. working with SPDIF. Clemend from the alsa-dev team suggested the following:

"""
Try changing /usr/share/alsa/cards/USB-Audio.conf. Dont add an entry to
the USB-Audio.pcm.iec958_device list near the top, but go to the bottom,
to the USB-Audio.pcm.iec958.0 definition, and change this:

USB-Audio.pcm.iec958.0 {
        @args [ CARD AES0 AES1 AES2 AES3 ]
        @args.CARD { type string }
        @args.AES0 { type integer }
        @args.AES1 { type integer }
        @args.AES2 { type integer }
        @args.AES3 { type integer }
        @func refer
        name {
                ...(lots of stuff)...
        }
        default {
                ...(lots of stuff)...
        }
}

to this:

USB-Audio.pcm.iec958.0 {
        @args [ CARD AES0 AES1 AES2 AES3 ]
        @args.CARD { type string }
        @args.AES0 { type integer }
        @args.AES1 { type integer }
        @args.AES2 { type integer }
        @args.AES3 { type integer }
        type hw # no @func
        card $CARD
        device 1
}
"""

I believe this fix ignores card-identification and assigns ALL USB soundcards so that iec958 is on device 1 rather than device 0. It is a hack because I cannot use other USB for iec958 cards but currently that is not a requirement so I am happy.

When I made the fix alsa picked it up without needing a restart i.e. I when I run
     aplay -L | grep -A 2 iec958
I get
    iec958:CARD=Ed,DEV=0
    Xonar U7 Echelon Ed., USB Audio #1
    IEC958 (S/PDIF) Digital Audio Output

Pulseaudio needed restarting to pick up the change and then everything worked well.

I will make a better fix when my Linux version supports the alsa release which has support or special characters.

Thank you again or helping me resolve this.

=======================================================================================

aoandr - I have a friend who has an original Asus Xonar U7 (which identifies itself to Alsa as "Xonur U7"). I have helped him get this working with iec958.

This worked for him:

    aplay -l [ to identify the card]
    amixer -c[x] sset 'IEC958 In' on [to ensure it is unmuted in alsa - [x] is the card number from aplay -l]

add the
USB-Audio.pcm.iec958_device {
        "Xonar U7" 1
...
}
to USB-Audio.conf

restart Pulseaudio and alsa (a reboot is easier than killing everything)

All worked after this for his Xonar U7