[Openvortex-dev] Src Cleanup

[Manuel Jander]

Hi everyone,

In my opinion the only really important thing to be cleaned up before 
releasing a first
version of the ALSA driver is the damn ugly Chip'n Dale bug. I think 
that having more insight
of the real meaning of the arguments of the function 
vortex_src_setupchannel() would help
a lot finding this out. Indeed the argument marked as "?" are totaly 
unknowm, and by know i just
figured out some values that "just work" for the AU8820 but not for the 
AU8830.

vortex_src_setupchannel(vortex, src, cvrt, 0, 0, ?, dir, 0, 0, ?);

The last argument, is either 0 or 1 (it sets the "throttle source" bit).
The 6th argument could be upto 4 bit wide, and it semes to be related 
with the SRC number being
used (not necesarily true). The AU8830 and AU8820 have 16 SRC's so that 
fits.

The current driver uses for each ADB DMA channel the SRC's i*2 and 
i*2+1, where i is the number
of the ADB DMA channel. This isn't the best alternative, but it ensures 
that there are always 2 SRC
avaiable for each ADB DMA channel.
The AU8830 has 32 ADB DMA channel and only 16 SRC: No idea how this 
should fit together.

There are 32 or 64 WT DMA channels, but they are handled different. They 
have bo routes for the SRC stuff.
They have Statically routes SRC inside of the "WT" block, an the output 
of the individually processed
channels are routed somewhere (ADB addresses are unknown) to the codec. 
THere is a generic
wt_setregister() functions, which i suspect is the one used by the 
WaveTable engine to control the
WT channels block, to change SRC settings, and possibly some special 
effects. The code for doing this
is not contained in the Linux binary driver, so if we want to implement 
the WaveTable we need to
sniff the Windows driver. Disassembling it is rather useless, inserting 
a sniffer would be easier.
Can anybody recommend a tool to disassemble, modify and recompile L type 
VXD's ? Maybe
a cracking tool :) ?

So, i'm extremely busy right know, so i wanted to ask if someone else 
could take a look at this ?
I could continue working on this issue in about 2 weeks, but come one 
guys, specially those who
havent coded anything, this your chance to do something really cool 
important. This code will
be part of the linux kernel 2.6 some day :) !!

Best Regards

Manuel Jander.