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...
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