Hi there,

I am looking for help with getting my SPDIF output working from my onboard soundcard (Intel ICH5), with Fedora Core 2 (kernel upgraded to 2.6.8-1.521smp) - my ultimate aim is to setup MythTV.

My PC is a Hoojum Cubit P4, which uses a Shuttle FB61 motherboard based on the Intel 865G/ICH5 chipset. I am using an optical SPDIF cable to connect to a Sony DAV-SC5 DVD/Home Theatre System. BTW, the cable is OK as digital audio works perfectly when I am running Windows XP. Also, the analogue line out works fine in Linux.

I have read the excellent Fedora Mythology FAQ, and looked at the ALSA config page for the Intel 8x0 driver.

I have used gnome-alsamixer to set what I have read are the correct IEC958 settings (for convenience I've used amixer to dump the settings):
Simple mixer control 'IEC958',0
Capabilities: pswitch pswitch-joined cswitch cswitch-joined
Playback channels: Mono
Capture channels: Mono
Mono: Playback [on] Capture [on]
Simple mixer control 'IEC958 Input Monitor',0
Capabilities: pswitch pswitch-joined
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'IEC958 Playback AC97-SPSA',0
Capabilities: volume volume-joined
Playback channels: Mono
Limits: 0 - 3
Mono: 0 [0%]

I've noticed that setting the 'Analog to IEC958 Output' flag in gnome-alsamixer sets the PCM light on my DAV-SC5, indicating some kind of SPDIF signal, but alas the output is very quiet at my speakers (presumably some kind of unwanted internal leakage?)

Does anyone have any ideas how I can debug this further? Any help would be much appreciated.

Thanks,


For reference, here are some extra details:

/var/log/messages
Nov 4 16:40:23 htpc kernel: intel8x0_measure_ac97_clock: measured 49319 usecs
Nov 4 16:40:23 htpc kernel: intel8x0: clocking to 48000

/sbin/lspci:
00:00.0 Host bridge: Intel Corp. 82865G/PE/P DRAM Controller/Host-Hub Interface (rev 02)
00:01.0 PCI bridge: Intel Corp. 82865G/PE/P PCI to AGP Controller (rev 02)
00:1d.0 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI #1 (rev 02)
00:1d.1 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI #2 (rev 02)
00:1d.2 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI #3 (rev 02)
00:1d.3 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI #4 (rev 02)
00:1d.7 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB2 EHCI Controller (rev 02)
00:1e.0 PCI bridge: Intel Corp. 82801BA/CA/DB/EB/ER Hub interface to PCI Bridge (rev c2)
00:1f.0 ISA bridge: Intel Corp. 82801EB/ER (ICH5/ICH5R) LPC Bridge (rev 02)
00:1f.2 IDE interface: Intel Corp. 82801EB (ICH5) Serial ATA 150 Storage Controller (rev 02)
00:1f.3 SMBus: Intel Corp. 82801EB/ER (ICH5/ICH5R) SMBus Controller (rev 02)
00:1f.5 Multimedia audio controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) AC'97 Audio Controller (rev 02)
01:00.0 VGA compatible controller: ATI Technologies Inc Radeon R350 [Radeon 9800]
01:00.1 Display controller: ATI Technologies Inc Radeon R350 [Radeon 9800] (Secondary)
02:06.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)
02:08.0 FireWire (IEEE 1394): VIA Technologies, Inc. IEEE 1394 Host Controller (rev 80)

lsmod:
Module Size Used by
snd_intel8x0 32621 6
snd_ac97_codec 60613 1 snd_intel8x0
snd_pcm 81733 1 snd_intel8x0
snd_timer 25157 1 snd_pcm
snd_page_alloc 12233 2 snd_intel8x0,snd_pcm
gameport 7617 1 snd_intel8x0
snd_mpu401_uart 9793 1 snd_intel8x0
snd_rawmidi 23525 1 snd_mpu401_uart
snd_seq_device 10313 1 snd_rawmidi
snd_mixer_oss 17985 2
snd 47397 16 snd_intel8x0,snd_ac97_codec,snd_pcm,snd_timer,snd_mpu401_uart,snd_rawmidi,snd_seq_device,snd_mixer_o ss
soundcore 10785 3 snd
autofs4 20165 0
sunrpc 128805 1
8139too 24257 0
mii 7617 1 8139too
floppy 54481 0
sg 33377 0
microcode 10209 0
vfat 15169 1
fat 40161 1 vfat
dm_mod 49477 0
joydev 11009 0
hci_usb 16193 0
bluetooth 42053 1 hci_usb
uhci_hcd 30553 0
ehci_hcd 29893 0
button 8793 0
battery 11085 0
asus_acpi 13017 0
ac 7373 0
ext3 99497 1
jbd 58457 1 ext3
ata_piix 9541 3
libata 33221 1 ata_piix
sd_mod 20801 4
scsi_mod 102025 3 sg,libata,sd_mod


# vi /etc/modprobe.conf
alias net-pf-10 off
alias eth0 8139too
alias scsi_hostadapter ata_piix

# ALSA portion
alias char-major-116 snd
alias snd-card-0 snd-intel8x0
install snd-intel8x0 /sbin/modprobe --ignore-install snd-intel8x0 && /usr/sbin/alsactl restore >/dev/null 2>&1 || :
remove snd-intel8x0 { /usr/sbin/alsactl store >/dev/null 2>&1 || : ; }; /sbin/modprobe -r --ignore-remove snd-intel8x0

# OSS/Free portion - card #1
alias sound-slot-0 snd-card-0
alias sound-service-0-0 snd-mixer-oss
alias sound-service-0-1 snd-seq-oss
alias sound-service-0-3 snd-pcm-oss
alias sound-service-0-8 snd-seq-oss
alias sound-service-0-12 snd-pcm-oss

# OSS/Free portion - card #2 (cmipci)
alias sound-slot-1 snd-card-1
alias sound-service-1-0 snd-mixer-oss
alias sound-service-1-3 snd-pcm-oss
alias sound-service-1-12 snd-pcm-oss

alias usb-controller ehci-hcd
alias usb-controller1 uhci-hcd