Re: DXS broken with some cards in 1.0.X in module snd-via82xx?

[Maggio <voloterreno@tin.it>]

Sergey Vlasov wrote:

>On Mon, Mar 01, 2004 at 03:00:41PM +0100, Maggio wrote:
>  
>
>>I was just wondering if the DXS support in 1.0.X has broken the 
>>DXS_SUPPORT=1 with some cards .
>>
>>I have an Abit KV7 Motherboard , and I use snd-via82xx for sound .
>>
>>I use this module from the version "0.9.8" , and I've never had any 
>>problems in enabling "dxs_support=1" with the 0.9.X series of the 
>>drivers , yesterday , by trying 1.0.2c and today the 1.0.3 versions of 
>>the kernel modules , I've noticed that ALSA doesn't work anymore with 
>>DXS_SUPPORT=1 , because the sound is garbled  , and I can only use DXS 
>>with DXS_SUPPORT=4 .
>>
>>What's up?
>>    
>>
>
>I suspect that dxs_support=4 is really the correct value in most (if
>not all) cases.  The resampling engine in VT82xx has a register for
>the source sample rate, but does not have any register to indicate
>the destination sample rate.  Unless the controller snoops the AC'97
>accesses in some way, this probably means that the destination
>sample rate is fixed at 48000 Hz.  I'm not sure what really happens
>when the codec is set to VRA mode in this case - probably this
>depends on quirks of a particular codec.  On my ASUS A7V8X (VT8235
>and ALC650) both dxs_support=1 and dxs_support=4 seem to work
>fine...
>  
>
dxs_support=4 works well for me in any cases , with 0.9.8 I don't hear 
(apparently) any difference between dxs_support=1 and dxs_support=4 , 
but with  1.0.2c/1.0.3 for me dxs_support=1 is pretty unusable , because 
of garbaged sound . I've just noticed that if I enable first 
dxs_support=4 , and then "rmmod" the driver , and then again reloading 
the driver with dxs_support=1 I get garbaged sound also with 0.9.8 . 
This is very obscure to me ...

I don't anyway completly understood how NO_VRA works and what this do , 
and what you lose what using NO_VRA instead of  VRA .

Thanks

Marcello


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