Re: AC97 sound problems with current

> Date: Wed, 26 Mar 2003 22:43:17 -0700
> From: Scott Long <scott_long_at_btc.adaptec.com>
> 
> Orion Hodson wrote:
> > Kevin Oberman writes:
> > |
> > | After upgrading my laptop from STABLE to CURRENT on 3/14 I have been
> > | having problems with GnomeMeeting. Often the sound is badly broken with
> > | 'spurts' of sound with silent gaps in between. This was never the case
> > | with STABLE. Other times it's fine.
> > |
> > | When I looked at my dmesg output I noticed some changes between STABLE
> > | and CURRENT for the pcm0 device. Under STABLE I only got two messages:
> > | pcm0: <Intel 82801CA (ICH3)> port 0x18c0-0x18ff,0x1c00-0x1cff irq 11 at 
> > device 31.5 on pci0
> > | pcm0: <Analog Devices AD1881A ac97 codec>
> > | Under CURRENT I get a third:
> > |
> > | pcm0: measured ac97 link rate at 512000000 Hz
> > 
> > There is a calibration step in the driver to determine the clock rate of the 
> > AC97 link.  What you are seeing is the calibration step failing and setting a 
> > bogus ac97 link rate.  I took a cursory look a couple of weeks back and it 
> > smelt like the timecounter initialization point changed, but haven't gotten 
> > around to looking closer and fixing the driver.
> 
> If this were true then I'd be very concerned.  Let me know what you
> find.  For what it's worth, my ICH3 setup is still working fine when
> loaded at boot, though my kernel is about 2 weeks old.

I have a system with problems and would be happy to help out as much as
I have the time for. Unfortunately, I have a project due at work on
Monday, and will be on vacation the rest of the week (but on line
Tuesday and Wednesday).

I'm afraid that I have never written a driver for FreeBSD, so I may be
of limited help. I have written drivers or other OSes, but they were all
written in assembly, not C and I wrote the last one at least 15 years
ago. 

But I am will to do what I can, at least test code others provide.

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