The short answer: use pr_debug instead of printk. The long answer: (This is the answer I got from stackoverflow question that I had asked for similar question I was having:) Each kernel subsystem usually has its own printk format. So when you are using network subsystem, you have to use netdev_dbg; when you are using V4L you have to use v4l_dbg. It standardizes the output format within the subsystem. ... You have got the warning because you are using prink() which is the raw way to print something. Depending on what you are coding you should use a different print style: printk(): never pr_debug(): always good dev_dbg(): prefered when you have a struct device object netdev_dbg(): prefered when you have a struct netdevice object [something]_dbg(): prefered when you have a that something object For the full answer see https://stackoverflow.com/questions/22077540/order-of-preference-printk-vs-dev-dbg-vs-netdev-dbg --- Yogesh On 5 April 2014 10:32, HABI S RAVI <habisbc@xxxxxxxxx> wrote: > Hi, > I am trying to fix a coding issue . I get the following warning when my > module is checked with checkpatch.pl. > How can i remove the warning. I see a lot of drivers using printk() > function. > > $ perl ~/linux-stable/scripts/checkpatch.pl -f hello.c > WARNING: Prefer netdev_dbg(netdev, ... then dev_dbg(dev, ... then > pr_debug(... to printk(KERN_DEBUG ... > #6: FILE: hello.c:6: > + printk(KERN_DEBUG "Hello World!\n"); > > WARNING: Prefer netdev_dbg(netdev, ... then dev_dbg(dev, ... then > pr_debug(... to printk(KERN_DEBUG ... > #12: FILE: hello.c:12: > + printk(KERN_DEBUG "hello module unloaded\n"); > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > -- DREAM IT, CODE IT _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
