Stop dereferencing 'r' unconditionally.  Maybe it is NULL when ISA mode and using polling mode.
Stop dereferencing 'r' unconditionally.  Maybe it is NULL when ISA
mode and using polling mode.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase