On 7 July 2015 at 16:11, Sébastien Hinderer <Sebastien.Hinderer@ens-lyon.org
wrote:
Hi Luis,
Many thanks for your prompt and helpfulresponse!
Do you have the relevant DEBUG macros activated in your kernel's configuration?
Perhaps not...
Read this, thanks. But that has nothing to do with KConfigmacros, has it?
http://elinux.org/Debugging_by_printing
If not, activate them. Or if in a pinch, switch to using pr_alert() for development.
What surprises me is that I made sue the message appears inthe .ko file and it was there,whereas it seems pr_debug discards its argument at compile time. Or is it at execution time?
Thanks!
Sébastien
Compile time. pr_debug() is meant only for development and discarded for "production" builds. pr_debug(), which is ordinarily an empty macro that discards its arguments at compile time. To enable debugging output, build the appropriate file with -DDEBUG by adding CFLAGS_[filename].o := -DDEBUG That is the key part there. But it is good to also check the options you have in: make menuconfig-> Kernel Hacking Enjoy, Luis