Documentation: expand/clarify debug documentation
authorDan Streetman <ddstreet@ieee.org>
Wed, 4 Jun 2014 23:11:44 +0000 (16:11 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 4 Jun 2014 23:54:17 +0000 (16:54 -0700)
commit6e099f557d9c6797c3ee3ee7b5c8cebe543ec1cc
treee96a0d9a951dbc494543cf563345c2f6115222f2
parent6d9bcb621b0b0a20604cbdb298c4487e44dd0da2
Documentation: expand/clarify debug documentation

The pr_debug() and related debug print macros all differ from the normal
pr_XXX() macros, in that the normal ones print unconditionally, while
the debug macros are compiled out unless DEBUG is defined or
CONFIG_DYNAMIC_DEBUG is set.  This isn't obvious, and the only way to
find this out is either to review the actual printk.h code or to read
CodingStyle, and the message there doesn't highlight the fact.

Change Documentation/CodingStyle to clearly indicate that pr_debug() and
related debug printing macros behave differently than all other pr_XXX()
macros, and attempt to clarify when and where the different debug
printing methods might be used.

Add short comment to printk.h above the pr_XXX() macros indicating that
while these macros print unconditionally, pr_debug() does not.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Cc: Joe Perches <joe@perches.com>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/CodingStyle
include/linux/printk.h