I just got a macbookpro (mid2009 version) with a new nvidia chipset.
there is no sound at all. neither via the built-in speakers nor via out-jack.
i tried aplay -D myfile.wav with everything from aplay -L as well.
i also tried a recent snapshot (alsa-driver-20090626.tar.bz2) as well as gentoo ebuilds alsa-headers-9999 and alsa-driver-9999 (which uses git to pull recent versions).
so here's a little information i can gather:
$ lspci -s 00:08.0 -v 00:08.0 Audio device: nVidia Corporation MCP79 High Definition Audio (rev b1) Subsystem: nVidia Corporation Device cb79 Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 23 Memory at d3480000 (32-bit, non-prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: HDA Intel Kernel modules: snd-hda-intel
alsa-info: http://www.alsa-project.org/db/?f=80e89b82fec184b68a88b9ed4128544a276775fc
modinfo snd-hda-intel: http://www.nopaste.com/p/a3B7miINP
i also found a thread about that problem (w/o solution obviously):
http://www.uluga.ubuntuforums.org/showthread.php?t=1188849&page=2
hope that's all information necessary.
if i can i'd love to help in some way.
thanks