The print() routine is called by the kernel when it has detected an exceptional condition (such as out of space) in the device. To display the message on the console, the driver
should use the cmn_err(9F) kernel function. The driver should
print the message along with any driver specific information.
The print() routine should return 0 for success, or the appropriate error number. The print routine can fail if the driver implemented
a non-standard print() routine that attempted to perform error logging, but was unable to complete the logging for whatever reason.