Do we need KBUILD_MODNAME to be defined?

I have the same problem described in this e-mail (unrelated to this driver):

>>"Sponsel Carsten (ext)" <[email protected]> wrote:
>>I have a makefile which builds my module using the new kbuild
>>system of kernel 2.6. As a result i will get a .o and a .ko
>>module file which i try to load via insmod. Both of these
>>file return the "invalid module format" error. The logfile
>>does not give further information on the error. What is
>>the new module format? Is there any information about it?
>>I've read the kbuild documentation and lots of newsgrep
>>entries but nothing helped me... Is there a possibility
>>to get more information about my specific error? Has anyone
>>a solution. I'm beginning to curse the new kernel :-((((
...
>The most common error seems to be not setting KBUILD_MODNAME
>somewhere. This will result in that message. This wasn't
>needed in 2.4.
>-Andi

I'm in the RTFM process right now, but I did try to find KBUILD_MODNAME in
the at76c503 latest cvs, and it's not defined.  Does anyone know if it's
really required?  I tried to #define KBUILD_MODNAME "usbdfu" (just tried
that one for starters) and it didn't help ... still says invalid module
format.

I also tried module-init-tools-3.0 to make sure it wasn't my insmod.  It's
not.

--Chris