ML403 / ALSA driver for AC97 Controller

Timur Tabi timur at
Thu Aug 9 08:16:59 EST 2007

On Aug 5, 2007, at 4:00 AM, Joachim Förster wrote:

> Meanwhile, I had a _very_ short look into ASoC ... and I don't really
> know ... My driver already uses the AC97 Layer of ALSA, so in some way
> the codec is already separated from the controller. Xilinx' AC97
> Controller Reference does have some very bad impact on the codec which
> forced me to implement codec register shadowing ... hmmmm, I have to
> look at it (ASoC) again - as soon as there is more (free)time ...

I've written an ASoC driver (not yet published, though).  ASoC is  
good when the codec is mix-and-match with the transport mechanism (eg  
I2S or AC97), and the transport hardware is physically separate from  
the DMA hardware.  Now, I don't know much about AC97 or the AC97  
driver in ALSA, so I can't tell you whether AC97 drivers in general  
should be ASoC.

I'm on vacation this week.  Can you send me an email with a pointer  
to your source code, because I think I lost the original post on this  
thread?  I'll take a look at it next week and let you know whether  
you should consider ASoC.

Also, ALSA patches should be posted against the head of the ALSA  
Mercurial tree, not Linus' 2.6.22 branch, which is already outdated  
by ALSA standards.  And we should be having this conversation on alsa- 

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