i810 audio fixes 1/2

[Mike Hearn]

On Sat, 27 Mar 2004 14:36:31 -0500, Robert Reif wrote:
> Another problem is that drivers support different formats in different  modes.
> Because of software emulation in alsa, a driver may appear to support any
> format but then fail when you try to mmap it because then software conversions can't
> come into play.  

I talked with one of the ALSA developers on IRC a day or two ago, and he
appeared to think mmap would work regardless of what plugin chain was in
use (resampling/conversion is implemented in alsa plugins). He said if it
didn't work it was a bug.

Anecdotal evidence seems to suggest this works now too. I was playing
22khz/8bit sample  - the winamp demo file -  on my i810 card and it was
using MMAP access yet still able to play (for a few seconds before bailing
with an assert in alsalib).

IIRC in XP DirectSound primary buffers no longer correspond to the sound
cards memory, they are just like any other and sent to the XP kernel
mixer. Is it possible the same is now true of ALSA?

thanks -mike