PROBLEM: OSS/MAD16 not available to compilation of kernel

["erlk ozlr" <erlk.ozlr@gmail.com>]

Hi,
I'm using linux 2.6.17 and I want to compile the mad16 driver but "at
least" CONFIG_SOUND_MAD16 is not present in "<source
root>/sound/oss/Kconfig" which makes it unchoosable in the `make
<something>config`, but there is still presence in the
"/sound/oss/Makefile".
I said "at least" because adding "CONFIG_SOUND_MAD16=m" in the
".config" file doesn't help : when I do `make modules_prepare`, it
removes the line, and I add it again then do `make modules
SUBDIRS=sound/oss` (well, I don't want to compile the whole kernel and
modules, I only lack mad16 ; I'm telling it because it perhaps has
consequences), it produces warnings (I don't know if it's the same
problem) but I have a mad16.ko.
Here is some log (maybe it isn't interesting) : """
  Building modules, stage 2.
  MODPOST
WARNING: sound/oss/cs4232.o - Section mismatch: reference to
.init.text: from .text between 'cs4232_pnp_probe' (at offset 0x5d) and
'unload_cs4232'
WARNING: sound/oss/mad16.o - Section mismatch: reference to
.init.data:mpu_io from .text after 'init_module' (at offset 0x15b)
"""
then follows many lines like this last one (the offset and the
"reference to" do change)

I can't tell you yet if the mad16.ko works because I'm lacking some
cross-kernel-compilation knowledge too : it says "invalid module
format", I checked the gcc version, building against the same x.y.z
version kernel source (please notice the subtly silent newbie-question
:-) ), and both computers are i386 (as says `file mad16.ko`).

ah, last thing, the report-bug-howto tells me to give keywords, so
here some :-) : modules, sound, obsolete, oss, mad16

thanks if you can fix or explain it :-)