Make sure the name of C functions are in small letters or same as fortran’s. C is case - sensitive, Fortran is not. SO make sure ‘cases’ of both the functions are same.
Another thing : are using underscore with C functions to make them callable from Fortran ? cause if you are then remove that underscore and add this to your Fortran compiling options ( in make file or wherever) " -assume nounderscore " and then you dont need underscores. (I Assume you are using ifort).
also you have to compile ifort like given in the nvidia Fortran example… linking -lcudart together along with the .o object file
I put my C functions in small case and I used to add an underscore at the end of them to have a compatibility with ifort.
For the first idea I’m using some external libraries which are not compiled with the “-assume nounderscore” so I don’t think it will work fine. But I’ll test it anyway.
I’ll ask the second thing to my system admin, cause I don’t know what he did.