[alsa-devel] CMI8788/AV200/Oxygen Volume Controls in alsamixer (oxygen_mixer.c:dac_volume_get())

[John Utz]

Sorry in advance about how i write mail today, i am working from home so i have to use exchange webmail.

-----Original Message-----
From: Clemens Ladisch [mailto:clemens at ladisch.de]
Sent: Fri 1/23/2009 5:51 AM
To: John Utz
Cc: ALSA Developers
Subject: Re: [alsa-devel] CMI8788/AV200/Oxygen Volume Controls in alsamixer (oxygen_mixer.c:dac_volume_get())
 
John L. Utz III wrote:
> It appears to me that these functions are attempting to work on all of 
> the channels at once instead of just choosing Master, Front, Rear, 
> Surround, or what have you:

Yes, the "Master" control is one control with eight channels.

JU Argh, yet another implementation strategy from a vendor. Too bad, but remember, this is why we use ALSA now instead of OSS. :-)

> this leads to a rather awkward result in alsamixer where there are 5 
> volume controls called "Master":
> 
> < Master >  Master    Master    Master    Master
> 
> IMHO, it would be more desirable for them to say:
> 
> < Master >  Front     C/LFE     Surround  Rear Surr

Yes.

Alsamixer chooses to display an eight-channel control this way.  This
can be considered a bug in alsamixer.

JU It *could*, but that's probably an impractical perspective. zillions of other drivers present this data in the way that amixer, alsamixer and many other mixers expect. 

Best regards,
Clemens