There are rate-limiting and one-shot extensions to the dev_*, pr_*, and printk family
of functions:

• printk_ratelimited(), pr_*_ratelimited(), and dev_*_ratelimited() print no more than 10 times in a 5 * HZ interval
• printk_once(), pr_*_once(), and dev_*_once() will print only once

And you also have utility functions to dump a buffer in hexadecimal, for example, print_hex_dump_bytes().