Mysterious sound card lottery

lucmove · 07-10-2007, 12:58 PM

I upgraded to Slackware 12 this weekend and can't solve this (among several other problems):

I have a PCI Sound Blaster Live! sound card. It worked flawlessly in Slack 11. Now Slackware seems to think that I have 2 sound cards. The Sound Blaster Live! and some VIA 8237 thing.

I don't know what that second card is, maybe it is the onboard sound system, which I have disabled in the BIOS and never bothered me until I installed Slack 12. The problem is that one is /dev/mixer and the other one is /dev/mixer1, and I can never tell which one is going to be which in the next boot. It seems to be completely random, like a lottery.

When the OS boots up with the VIA 8237 thing as /dev/mixer, I don't have any sound in the loudspeakers, except loud feedback because the sound card lottery also creates a problem with the microphone. The microphone is connected to the SB Live! card, but it does pick up ambient sound although SB Live! won't give me any output in the loudspeakers. But there is "something" in the loudspeakers that the microphone picks up, so the system boots up with the loudspeakers screeching with feedback. The way to make them stop screeching is very annoying: I have to open kmix, select the SB Live! card in a drop-down (because the VIA card is selected), then click the Input tab, then click a button in the Mic slider then click a button in the Line slider. Or I can run rexima and tweak /dev/mixer1. That can be partially automated, but it's still annoying and I haven't found out how to get the normal output from the SB Live! card. I just end up rebooting a few times until I win "the lottery" again, then everything runs normally.

I've run alsaconf and "configured" the sound card. I see that it changed the /etc/modprobe.d/sound file, but it didn't fix the problem. I also uncommented "blacklist emu10k1" and added "blacklist via82xx" in /etc/modprobe.d/blacklist. But none of that has been enough. Can someone please help me get rid of this VIA 8237 card?

bioe007 · 07-10-2007, 01:23 PM

AFAIK adding stuff to blacklist doesn't work for 2.6 kernels.. you might need to do something like

Code:

modprobe -rf via8xx

in your init scripts. (maybe in rc.alsa ? right after it modprobes everything? )

lucmove · 07-10-2007, 01:27 PM

Code:

#[507]~> modprobe -rf snd_via82xx
FATAL: Module snd_via82xx is in use.

Code:

#[508]~> lsmod | grep via
i2c_viapro             11668  0
snd_via82xx            26520  2
snd_ac97_codec         98980  2 snd_via82xx,snd_emu10k1
via_rhine              24968  0
mii                     8576  1 via_rhine
pata_via               12164  0
via_agp                12160  1
gameport               15112  3 snd_via82xx,emu10k1_gp
agpgart                31432  2 nvidia,via_agp
snd_pcm                72068  4 snd_pcm_oss,snd_via82xx,snd_emu10k1,snd_ac97_codec
snd_page_alloc         11528  3 snd_via82xx,snd_emu10k1,snd_pcm
snd_mpu401_uart        10496  1 snd_via82xx
snd                    47204  17 snd_seq_oss,snd_seq,snd_pcm_oss,snd_mixer_oss,snd_via82xx,snd_emu10k1,snd_ac97_codec,snd_pcm,snd_hwdep,snd_timer,snd_mpu401_uart,snd_rawmidi,snd_seq_device

I could be wrong, but it seems to me that I can't remove snd_via82xx without killing the module that is using it, which would also kill snd_emu10k1, which the SBLive card requires.

gbonvehi · 07-10-2007, 02:22 PM

Add in : /etc/modprobe.d/modprobe.conf

Code:

options snd_emu10k1 index=0
options snd_via82xx index=1

That way, the Sound Blaster Live will always be the first card.

By the way, if you won't use your other card, add the module to /etc/modprobe.d/blacklist so it won't be loaded.

bioe007 · 07-10-2007, 02:37 PM

iirc the stock slack12 kernel doesnt have forced module unloading... but thats ok. you can still kill all the sound modules then reload the ones you want. you could also add something to rc.alsa

Code:

if [ ! $DRIVER == "snd_via82xx" ]; then
  modprobe $DRIVER
fi

that snippet may be incorrect syntax (?) I'm not the worlds greatest scripter..

alternatively since the rc.alsa script just loads everything it finds in /lib/modules/'uname'/kernel/drivers/sound you might try just renaming the vi82xx.ko file to something rc.alsa wont recognize as a kernel module.

of course, the most elegant solution remains to recompile without the via support.

lucmove · 07-10-2007, 03:57 PM

gbonvehi, read my post again. I already added the unwelcome card to the blacklist file. It's not working.

bioe007, you do have a point. My Slackware 11 ran a custom kernel, I probably had removed support to extraneous sound cards. But recompiling a kernel is such a chore. I don't wanna go through all that again. Renaming the offending module file so rc.alsa won't find it is very tempting.

I am very optimistic about all these suggestions. I am going to try them now. But, incidentally, I just noticed that I have these two directories: /lib/modules/2.6.21.5 and /lib/modules/2.6.21.5-smp. I am running smp. Do I really need the other one? May I delete it to save space?

Thanks.

gbonvehi · 07-10-2007, 04:45 PM

I read that, but you said you added via82xx, not snd_via82xx, was it a typo?

Btw, I also added to /etc/modprobe.d/sound

Code:

alias snd-card-0 snd-emu10k1
alias sound-slot-0 snd-emu10k1

alias snd-card-1 snd-via82xx
alias sound-slot-1 snd-via82xx

lucmove · 07-11-2007, 01:58 PM

Back to the forum in a positive tone. The tips above worked - pretty much a combination of them all - no patience to isolate and check which one nailed it. The problem is gone. Better yet: music sounds a lot better than before. Maybe 12 comes with better drivers? I don't know, it just sounds great.

Regards.