ATI IXP400 issue : very low output

Pierre Emeriaud at
Sat Mar 9 14:04:16 UTC 2013

Hello list,

I have a sound issue with my recently-installed FreeBSD. The
motherboard has a ATI IXP400 with an ALC655 chip.

At first I thought that output wasn't working. But increasing the
volume on the amplifier I was using resulted in a *very* weak sound
output, which sounds like a leakage current being amplified. Whereas
I'm using an application (I've been testing with vlc) or directly
piping random to /dev/dsp0, I get the same output level.

ALC655 is AC96 rev2.3, so maybe it has something to do with 'jack
detection', but I not able to troubleshoot much further than I did.

OSS is not installed as I've been taught that it wasn't necessary to
have audio working, but I can install it if it can solve the issue.

% grep pcm /var/run/dmesg.boot
pcm0: <ATI IXP 400> mem 0xff6ff400-0xff6ff4ff irq 17 at device 20.5 on pci0
pcm0: <Avance Logic ALC655 AC97 Codec>

% pciconf -lv | grep -A 4 pcm
pcm0 at pci0:0:20:5:       class=0x040100 card=0xd0081631 chip=0x43701002
rev=0x01 hdr=0x00
    vendor     = 'ATI Technologies Inc'
    device     = 'IXP SB400 AC'97 Audio Controller'
    class      = multimedia
    subclass   = audio

% kldstat | grep snd
10    1 0xffffffff816af000 2c49     snd_atiixp.ko

Output of vmstat -i, cat /dev/sndstat, sysctl hw.snd and dev.pcm, and
mixer (all at 100) here :

Do you have any ideas on how to solve this issue?

Thanks in advance,

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