Hyperactive ICH2 sound (with workaround)

Craig Boston

unread,

Feb 26, 2003, 4:03:44 PM2/26/03

to

On a recently compiled current the sound from an Intel 82801BA
integrated sound chip seems to be accelerated (high pitched and too
fast). While it's amusing to listen to certain songs this way, I don't
think it should be the default mode of operation ;)

Relevant dmesg output:

pcm0: <Intel 82801BA (ICH2)> port 0xdc40-0xdc7f,0xd800-0xd8ff irq 10 at
device 31.5 on pci0
pcm0: <Analog Devices AD1885 ac97 codec>
pcm0: measured ac97 link rate at 512000000 Hz

and sysctl hw.snd.pcm0:
hw.snd.pcm0.buffersize: 16384
hw.snd.pcm0.vchans: 0
hw.snd.pcm0.ac97rate: 48000

Here is the output from another system with the same hardware running
5.0-RELEASE:

pcm0: <Intel 82801BA (ICH2)> port 0xcc40-0xcc7f,0xc800-0xc8ff irq 10 at
device 31.5 on pci0
pcm0: measured ac97 link rate at 55939 Hz

and the sysctl:
hw.snd.pcm0.buffersize: 16384
hw.snd.pcm0.vchans: 4
hw.snd.pcm0.ac97rate: 55939

So it looks like the AC97 link rate measurement isn't working right.
Manually setting it with "sysctl hw.snd.pcm0.ac97rate=55939" seems to
correct the problem.

Current from about a week ago was working fine. A kernel from last
night exhibits this problem, as does one cvsupped this morning. I'll go
trawling through CVS when I have some free time.

Not really a big deal, just wanted to make sure somebody was aware of
the problem and also to get the workaround into the mailing list
archives...

Craig

To Unsubscribe: send mail to majo...@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message

Jun Su

unread,

Feb 28, 2003, 9:20:06 AM2/28/03

to

When I load snd_ich module, I got the following output.
pcm0: <Intel 82801CA (ICH3)> port 0x18c0-0x18ff,0x1c00-0x1cff irq 9 at device
31.5 on pci0
pcm0: <unknown ac97 codec> (id=0x594d4803)
pcm0: measured ac97 link rate at 682666666 Hz

sysctl hw.snd.pcm0 :
hw.snd.pcm0.buffersize: 16384
hw.snd.pcm0.vchans: 0

hw.snd.pcm0.ac97rate: 682666666

uname -v:
FreeBSD 5.0-CURRENT #10: Fri Feb 28 11:53:30 CST 2003

I can play the sound, however the sound has lag. I am not sure if it is the
porblem casued by the rate. When I play the sound, I get the same problem in
the PR34942: http://www.FreeBSD.org/cgi/query-pr.cgi?pr=34942

Who can give some advice on this problem?

Jun

Kevin Oberman

unread,

Feb 28, 2003, 3:02:08 PM2/28/03

to

> From: Jun Su <Ju...@gmx.net>
> Date: Fri, 28 Feb 2003 22:19:49 +0800
> Sender: owner-free...@FreeBSD.ORG

>
>
> When I load snd_ich module, I got the following output.
> pcm0: <Intel 82801CA (ICH3)> port 0x18c0-0x18ff,0x1c00-0x1cff irq 9 at device
> 31.5 on pci0
> pcm0: <unknown ac97 codec> (id=0x594d4803)
> pcm0: measured ac97 link rate at 682666666 Hz
>
> sysctl hw.snd.pcm0 :
> hw.snd.pcm0.buffersize: 16384
> hw.snd.pcm0.vchans: 0
> hw.snd.pcm0.ac97rate: 682666666
>
> uname -v:
> FreeBSD 5.0-CURRENT #10: Fri Feb 28 11:53:30 CST 2003
>
> I can play the sound, however the sound has lag. I am not sure if it is the
> porblem casued by the rate. When I play the sound, I get the same problem in
> the PR34942: http://www.FreeBSD.org/cgi/query-pr.cgi?pr=34942
>
> Who can give some advice on this problem?

Could you clarify what you mean by "the sound has lag"? Do you mean
that it plays too slowly or that there is a time delay in playback?

It sure sounds like the test for sampling rate is fubar.

R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: obe...@es.net Phone: +1 510 486-8634