The concept behind device driver implies the use of peripheral 'devices' dedicated to specific tasks, such as PIO, UART, etc. (built-in on chip, or not). On current Linux systems operating at CPU clock speeds as high as in the range of a few hundred megahehtz, it would not be at all appropriate to consider handling IOs when a high rate repetition occurs; this happens, but waste a lot of processing of the system, therefore in the end all depends on your analysis of what more is being executed on the system,vand what is the demand for immediate response to the other tasks.