Then, run gdb on that module, and look up the offset with the list command. This will only work if you've compiled that module with -g to include debugging information. However, I prefer that bug reports be posted to my web site, so that they can be seen by others. If this is undefined, debugging code will not be compiled. If set to 0, the code is compiled but inactive.
Larger numbers specify increasing levels of verbosity.
This can be adjusted when the module is loaded, so output can be controlled on a per-module basis without recompiling. They are most useful if you have access to a datasheet for the corresponding controller chip. It can be used to directly access any card's attribute memory or common memory. For devices that are close relatives of normal ISA devices, you'll probably be able to use parts of existing Linux drivers. In some cases, the biggest stumbling block will be modifying an existing driver so that it can handle adding and removing devices after boot time.