An error is seen similar to the following when compiling the RealPort driver in Linux:
dgrp_net_ops.c:1229: error: dereferencing pointer to incomplete type
make[3]: *** [/usr/src/.../BUILD/dgrp-1.9/driver/dgrp_net_ops.o] Error 1
make[2]: *** [_module_/usr/src/.../BUILD/dgrp-1.9/driver] Error 2
make[2]: Leaving directory `/usr/src/kernels/2.6.26.3-14-i686''
make[1]: *** [build] Error 2
make[1]: Leaving directory `/usr/src/.../BUILD/dgrp-1.9/driver''
make: *** [build] Error 2
error: Bad exit status from /var/tmp/rpm-tmp.15543 (%build)
The 2.6.26.x kernel version is not supported in any of the Linux drivers due to inherent problems in this kernel. The 2.6.27 and higher kernels are supported as is 2.6.25 and lower.