Initializing and Unloading

The _init(9E) entry point first calls the ddi_soft_state_init(9F) function to initialize the soft state. If the soft state initialization fails, that error code is returned. If the soft state initialization succeeds, the _init(9E) entry point calls the mod_install(9F) function to load a new module. If the module install fails, the _init(9E) entry point calls the ddi_soft_state_fini(9F) function and returns the error code from the failed module install.

Your code must undo everything that it does. You must call ddi_soft_state_fini(9F) if the module install fails because the _init(9E) call succeeded and created a state pointer.

The _fini(9E) entry point must undo everything the _init(9E) entry point did. The _fini(9E) entry point first calls the mod_remove(9F) function to remove the module that the _init(9E) entry point installed. If the module remove fails, that error code is returned. If the module remove succeeds, the _fini(9E) entry point calls the ddi_soft_state_fini(9F) function to destroy the state pointer and the state structures for all instances of this device.