at76c503a doesn't work with gcc4. You should patch all source files and replace MODULE_PARM with module_param. New version of gcc removes MODULE_PARM as unneeded.
I made patch to fix this problem. It works for me and I think it would work with most new kernels (that support module_param). Simply add epatch ${FILESDIR}/at76-gcc4.diff to ebuild and put this patch into files. I think version bump isn't needed as it doesn't add any functionality.
Created attachment 81774 [details, diff] Patch for gcc4 support
Why don't you update this to later version of debian patches ( 4 in testing and 7 in unstable)? Maybe I can help to maintance this package but there is no bugs about it...
Created attachment 81782 [details, diff] New patch (for debian-7)
Created attachment 81783 [details] Ebuild that use debian-7 patch level.
Created attachment 81790 [details] Ebuild in text/plain
Created attachment 81791 [details] patch in text/plain
Created attachment 81793 [details, diff] Patch with ?correct? spacing
thanks, fixed