SB Live - Nothing but Buzzing

Ruler2112

Ruler2112

I have a system with FreeBSD 8.2/amd64 loaded on with a PCI SB Live sound card. It uses the EMU10Kx sound module which is configured to load automatically in /boot/loader.conf using
Code: 
snd_emu10kx_load="YES"

/dev/sndstat has the following in it:

Code: 
FreeBSD Audio Driver (newpcm: 64bit 2009061500/amd64)
Installed devices:
pcm0: <EMU10Kx DSP front PCM interface> (play/rec) default
pcm1: <EMU10Kx DSP rear PCM interface> (play)

The sound card shows up in the system:

Code: 
    vendor     = 'Creative Technology LTD.'
    device     = 'Sound Blaster Live! (Also Live! 5.1) - OEM from DELL - CT4780 (CT5880DCQ)'
    class      = multimedia
    subclass   = audio
none3@pci0:5:1:1:       class=0x098000 card=0x00201102 chip=0x70021102 rev=0x08 hdr=0x00

I initially set up the system, kldloaded the module manually, started kde as a user, and everything was great - this is when I added the line above to /boot/loader.conf so it'd happen at boot time. I compiled/installed a bunch of ports (LibreOffice, TightVNC, Firefox 3.6, Flash, GIMP, etc).

When I rebooted, the sound.ko and snd_emu10kx.ko modules loaded at boot just as they should. However, when I started KDE, a buzzing noise started coming from my speakers. As long as the sound system is active, the buzzing noise persists. The buzz fluctuates when KDE would ordinarily play a sound.

The only thing I can think of is that one of the ports I installed somehow conflicts with the KDE sound system, resulting in this behavior.

Any ideas of what I could try in the way of troubleshooting? Frankly, I'm at a loss of what to try next. (Other than to unplug my speakers so it doesn't drive me insane... ;) )
 
I made a discovery - it's not confined to within KDE. Using sndfile-play from the console to play a wave also results in static/buzz/crap. Now I'm really confused as to what's going on... :(
 
Very odd.... if I remove the line loading the snd_emu10kx module from /boot/loader.conf, reboot, and then load the module manually with kldload, it works perfectly. Booting with the module loaded automatically results in nothing but crap coming from the speakers.

I have a workaround (logging in as root and loading the module manually after every boot), but would like to not have to do this if possible. Advice appreciated.
 
I've noticed that when snd_emu10kx is loaded via loader.conf, it gives the pcm devices a different order than when the driver is loaded after the system boots. You could try adjusting the hw.snd.default_unit sysctl and see if that resolves the problem.
 
Good thought Adam. I tried it and found that no matter if I load snd_emu10kx from /boot/loader.conf or via kldload after the system is up, the sysctl entries are the same.

Code: 
# When loaded via loader.conf - sound is static/garbled
sysctl -qa |grep dev.pcm > snd.boot
sysctl -qa |grep hw.snd >> snd.boot

# Rebooted, loaded via kldload - sound is good
sysctl -qa |grep dev.pcm > snd.kld
sysctl -qa |grep hw.snd >> snd.kld

Both output files are the same. I'm at a loss to explain how or why it's happening. Since I have a workaround, it's a low priority for me, even though having to log in as root every time I reboot is a PITA.
 
You can always just edit /etc/rc.local to load the module. Then you won't have to do it manually each time.

Adam
 
Good call Adam, though /etc/rc.local is in Linux. :\ ;) I created a script in /usr/local/etc/rc.d to do what is needed and the sound is now loaded automatically after everything else is done. :)
 
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