nvidia wrecks alsa?

cerddwr · Posted: Thu Jul 26, 2007 5:15 pm Post subject: nvidia wrecks alsa?

I originally posted this in Multimedia, but further experimenting suggests a kernel problem.

My system uses the M-Audio 2496 card with alsa compiled as a kernel module. It was working perfectly until I did emerge -uD world. Now it plays all sound files at very slow speed and correspondingly low pitch. I mean _really_ slow, something like a quarter or less of the proper speed. It is the same whether I use mplayer, mpg123, audacious, or play an open .wav or .mp3 file in audacity.

I can get something approaching the proper speed and pitch, but unsteady sound, if I do

PaulBredbury · Watchman Joined: 14 Jul 2005 Posts: 7310

wyvern5 · Apprentice Joined: 11 Nov 2006 Posts: 161

Try configuring 2.6.21 from scratch. Keep a log of the changes you make -- you may be surprised how few things you actually *need*. That's how I do it -- no possibility of kernel config issues when I go from 2.6.x to 2.6.x+1.

cerddwr · Posted: Fri Jul 27, 2007 9:49 am Post subject:

I never expected anyone to make a psychic connection, I merely thought that someone might have encountered the problem before.

Following the instructions in the wiki:

Akkara · Posted: Fri Jul 27, 2007 11:52 am Post subject:

Perhaps something in X is playing sounds at 11KHz causing the card to set to that rate.

Try envy24control (might need to emerge alsa-tools). Click on Hardware Settings and check what Actual Rate reports as the sampling rate. If it is not what's needed (typically 44.1 or 48 KHz) you can try changing it by pressing the appropriate radio button. If it doesn't change it means something's holding the card open and need to find out what.

cerddwr · Posted: Mon Jul 30, 2007 12:51 pm Post subject:

Thank you Akkara, for that helpful tip. envy24control reported a frequency of 8000. Unticking the "locked" box and clicking on the 44100 radio button restored the sound to normal. However the problem comes back after rebooting, so I shall have to look more deeply into why this is occurring. Clearly, something is being overwritten at boot-up.

So, partly solved.
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crumbs516 · n00b Joined: 13 Dec 2005 Posts: 35

I have the same slow sound problem. It takes several seconds to play a single second of a sound file. I have observed in Audacious and totem movie player using different file formats.

I followed the wiki when nothing else worked http://gentoo-wiki.com/HOWTO_Compile_Kernel_with_ALSA. I've also read posts 571828 and 572525. Changing

crumbs516 · n00b Joined: 13 Dec 2005 Posts: 35

I wasn't able to fix the problem using other methods so I used the suggestion to downgrade the kernel verison to at least 2.6.18. Here's a quick code version of what I did that worked. The code below assumes that you already followed the gentoo ALSA guide and set up sound configuration files.

crumbs516 · n00b Joined: 13 Dec 2005 Posts: 35

Previously I had downgraded the kernel. That worked fine until HAL required a newer kernel, so I decided to try to fix the audio again. I can get audio to play in mpg123 just fine but then the slow problem comes back after boot. I'd really appreciate some suggestions for how to get the audio to stop breaking on reboot. I've tried to be as complete as possible where I deviated from the ALSA howto wiki entry.

What I did to get the MAudio Audiophile 2496 Card to "Mostly" Work:

http://gentoo-wiki.com/HOWTO_ALSA_Complete_%28includes_dmix%29

Code:

rm /etc/asound.state
rm /var/lib/alsa/asound.state
vi /usr/share/alsa/alsa.conf
# change "defaults.pcm.dmx.rate 48000" to "defaults.pcm.dmx.rate 44100"
/etc/init.d/alsasound restart
mpg123 song.mp3; # works
aplay -d plug:dmix sound.wav; # works
madplay -v sound.mp3; # Error: audio: esd_open_sound() failed
audacious; # no play. error posted elsewhere as continuation of another post

What has to be done each time I boot to remove slow sound. I'd really appreciate suggestions on how to fix this problem. I got this idea from the note on the ALSA wiki about "No Sound, Mixers Adjusted: When switching between built-in ALSA, kernel modules, and alsa-driver..."

Jaglover · Posted: Sun Feb 03, 2008 5:26 am Post subject:

PaulBredbury · Watchman Joined: 14 Jul 2005 Posts: 7310

crumbs516 · n00b Joined: 13 Dec 2005 Posts: 35

Yes, it may be true that amixer can perform similar functions to alsamixer. But the alsamixer step isn't necessarily part of the problem.

The problem is that every time I reboot some setting is changed and ALSA plays sound at the wrong sample rate. Reseting the alsa state and unmuting sound with alsamixer removes the problem, but it is annoying to have to log in as root at console to fix the sound.

red-wolf76 · Posted: Fri Mar 07, 2008 8:37 pm Post subject: