kernel loglevel

Dear all, I am working on a kernel module that incorporate both pr_debug and pr_warn. I would like to see pr_debug messages from dmesg. What I followed is to specify kernel parameter by saying "loglevel=7". This can be seen confirmed from /proc/cmdline. But still, I donot get pr_debug level messages either from dmesg or from /var/log/messages. I also tried echo 7 > /proc/sys/kernel/printk. It does not return what I expect, either. Let me know what I am missing. Thank you very much in advance. Cheers, Wenda Ni, Ph.D.