strange soundcard behavior- alsa, soundblaster, kernel 2.6

DiscreteOnyxOrb · n00b Joined: 08 Apr 2004 Posts: 24

I've been trying to get sound working on my Dell 8100 for a few weeks now, and haven't gotten any further than I started. The sound is distorted and crackly. Turning down the volume levels to 50% and muting all unneeded items in alsamixer makes music listenable, but I can still hear a crackle/slowdown whenever I open a new window. I can get an effect like a digital turntable scratch by sliding the scrollbar on mozilla (or anything) up and down quickly. Furthermore, when playing video the audio is particularly bad. If I cover up the video window (ogle, mplayer, xine--doesn't matter) with something like mozilla, the audio sounds fine, but as soon as I bring the video window to the foreground, sound goes all crackly. This happens for all video: divx on the hard drive, a dvd disc in the player, etc. The CPU level is normally around 7% with it covered up, 12% with it showing.

I'm using gentoo-dev-sources-2.6.4 (tried 2.6.3) with a Creative Soundblaster PCI 128 card. I've checked the card model number to make sure its the one for the ens1371 driver. I've tried alsa compiled in, or as modules. I've tried switching the PCI slots. I've even tried switching to a different ens1371 card. Same problem. I've also tried removing the nvidia module and using the default kernel one. I've tried with and without OSS emulation. I'd be willing to switch to OSS (though removing alsa is a pain), but I've read accounts that seem to indicate it won't be any better.

lsmod:
Module Size Used by
snd_ens1371 19620 1
snd_rawmidi 18560 1 snd_ens1371
snd_pcm 84744 1 snd_ens1371
snd_page_alloc 9348 1 snd_pcm
snd_timer 22020 1 snd_pcm
snd_ac97_codec 58244 1 snd_ens1371
snd 41656 7 snd_ens1371,snd_rawmidi,snd_pcm,snd_timer,snd_ac97_codec
soundcore 7520 1 snd
nvidia 1700652 10

/etc/modules.d/alsa:
# Alsa 0.9.X kernel modules' configuration file.
# $Header: /home/cvsroot/gentoo-x86/media-sound/alsa-utils/files/alsa-modules.c$

# ALSA portion
alias char-major-116 snd
# OSS/Free portion
alias char-major-14 soundcore

##
## IMPORTANT:
## You need to customise this section for your specific sound card(s)
## and then run `update-modules' command.
## Read alsa-driver's INSTALL file in /usr/share/doc for more info.
##
## ALSA portion
## alias snd-card-0 snd-interwave
alias snd-card-1 snd-ens1371
## OSS/Free portion
alias sound-slot-0 snd-card-0
## OSS/Free portion
alias sound-slot-0 snd-card-0
## alias sound-slot-1 snd-card-1
##

# OSS/Free portion - card #1
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
## 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 /dev/mixer snd-mixer-oss
alias /dev/dsp snd-pcm-oss
alias /dev/midi snd-seq-oss

# Set this to the correct number of cards.
options snd cards_limit=1
options snd-pcm-oss dsp_map=1

Please ask me if any more information would help. This is my first gentoo system.

einstein1981 · Posted: Wed Apr 14, 2004 3:29 am Post subject:

seems like you tried everything possible, so this might be a wild guess.
I had terrible sound with alsa, until I reconfigured the xmms equalizer (this fixed the all around sound problem)

doesn't hurt to check it out.

Also I remember installing that sound card on my grandfathers computer and even in windows the sound was terrible, the sound card was damaged , so i returned it and got a new one and all was fine.

do you have another kernel working, or maybe windows, to see if it's a soundcard problem?

well hope this helps
_________________
thesis.

DiscreteOnyxOrb · n00b Joined: 08 Apr 2004 Posts: 24

So I switched one of my ens1371 cards for my roommate's emu10k1 card. The most noticeable difference is that the distortion is more crackly, and when I slide a scrollbar up and down really fast I just hear a bunch of pops instead of a cool turntable mixing effect.

So I thought it might be something in the kernel, some option I should have/have not set. I simultaneously upgraded to 2.6.5 and gave genkernel a try....

I swear that it worked better the first time. Maybe not 100% smooth, but I was successfully watching Shaolin Soccer. Then a reboot, and the problem is back to stay.

My current suspicions are:
1. esd, will try killing it
2. the budget nvidia graphics card i have is fighting with sound, though not in any driver dependent way, will try another roommate swap experiment
3. alsa is FUBAR, and I should try to get depracated OSS working (after invoking the proper spirits to remove all traces of ALSA)
4. this is punishment for using the O3 CFLAG

einstein1981 · Posted: Sun Apr 18, 2004 6:13 pm Post subject:

did you enable alsa emulation?

It seems strange that you get terrible sound with alsa, and an emulk1 sound card.

maybe you should emerge sync and emerge world to get the lates alsa drivers , and try the alsa configuration guide, I think they use the same sound card that you have in the examples...

it's quite strange, more than a driver problem I would say it is a alsa config problem.

you are right about one thing, alsa is dificult to set up, but the results, for me, are better than oss.

give it another try.

there is also an emerge for your drivers, in the alsa guide they say how you should do it, follow it step by step and give it a try
_________________
thesis.

DiscreteOnyxOrb · n00b Joined: 08 Apr 2004 Posts: 24

You mean OSS emulation? I think I tried both with and without. Do I need it? Should I put oss in my USE flags? Tried versions of alsa drivers from 0.98 to 1.0.3. Tried emerging world. They do use the same sound card but the instructions for the 2.6 kernel are a little vague. Exactly what should I enable/disable in the kernel, and what should be a module?

Additionally, which packages do I need to emerge?

Does anything in my /etc/modules.d/alsa file look suspicious?

Suppose I just want to watch movies, with say ogle (uses alsa) what is the bare minimum alsa config I need? Perhaps simplifying things will help me isolate the problem.

I guess I should unmerge everything alsa related and delete the entry from rc.conf and delete the alsa module file before trying alsa again.

I'm tempted to do this and try OSS before giving ALSA another chance. I just want to watch movies.

As a last resort I could switch to the 2.4 kernel. This seems dangerous as this has been a 2.6 system from the start.

einstein1981 · Posted: Sun Apr 18, 2004 6:57 pm Post subject:

did you update the conf file when you tried to change the sound cars, because the config file is for the first card

DiscreteOnyxOrb · n00b Joined: 08 Apr 2004 Posts: 24

A_Bloke · n00b Joined: 19 Apr 2004 Posts: 2 Location: Skipton, Leeds

I've just had the same problem as you, and went through all the possible solutions (Throughout the forums), and in the end I emerged gnome-alsamixer, to find out that there is a rogue mixer level still at 100%, can't remember which now...just a suggestion.

A_Bloke
_________________
A_Bloke

DiscreteOnyxOrb · n00b Joined: 08 Apr 2004 Posts: 24

for some reason switching from a PCI Nvidia MX400 to a AGP Nvidia GeForce 5200 solved the problem.