i810 audio (AD1981A)

[Brian C. Huffman]

anyone?  Bueller...Bueller...

TIA,
Brian

---------- Forwarded message ----------
Date: Tue, 19 Nov 2002 11:09:33 -0500 (EST)
From: Brian C. Huffman <[e-mail]>
To: [e-mail]
Cc: Alan Cox <[e-mail]>, Peter Kundrat <[e-mail]>
Subject: Re: i810 audio (AD1981A)

Ok - so I have got this figured out a little more.  The Intel 845 board 
uses the AD1981A (AC97 compatible) BUT they attach the headphone out (of 
the codec) to the lineout on the motherboard...apparently b/c there's a 
headphone amp in the chip and this way you can just plug the headphones 
into the back of the computer.  :-(  Now looking at the latest drivers 
from OSS and ALSA, this looks to be common, however the register setup for 
the AD1981A is different from the others: AD1980, and AD1886...  
Therefore, the patches in ALSA to disable the headphone out don't work.  

If I can't find a way to write to the registers to make this work 
properly, I'd be happy just swapping what the mixer thinks the 
registers are for Main Volume w/ Headphone out.  Unfortunately, I tried 
this (with the kernel OSS) in linux/drivers/sound/ac97.h:

#define  AC97_RESET              0x0000      //
// #define  AC97_MASTER_VOL_STEREO  0x0002      // Line Out
#define  AC97_MASTER_VOL_STEREO  0x0004      // Line Out
//#define  AC97_HEADPHONE_VOL      0x0004      //
#define  AC97_HEADPHONE_VOL      0x0002      //

This still doesn't work, though!?  Can anyone direct me to what I might be 
doing wrong?

Thanks in advance!
Brian

> On Tue, 2002-11-12 at 19:43, Alan Cox wrote:
> 
> > The kernel knows which AC'97 chip is attached so it could be given a
> > table to specify chips where "volume" should either not be presented or
> > should be remapped. Do you know what AC97 chip is on your board (Linux
> > will print the info in the i810 load, windows and the manual probably
> > claim that you have that as your sound chip (typically "Analog
> > something" or "Crystal something").
> > 
> 
> 
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