How to see kernel pr_err error messages.

[reg at dwf.com]

Im looking at some kernel code, and there are 'pr_err' error messages in
it that would help me discover my problem.

However I dont see them printing anywhere.

What do I have to do to see these error messages?
A search with GOOGLE  and a grep of the code wasnt too useful, but
it seems possible that I need to set

    #define CONFIG_DEBUG

Is that true?  I see a lot of <something>_DEBUGs in the .config file
but no simple CONFIG_DEBUG, 

In any case, how do I get these things to print?
-- 
                                        Reg.Clemens
                                        reg at dwf.com