X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=Documentation%2FCodingStyle;h=7f1730f1a1ae2e9a6f368bdb10ff65f4568863d5;hb=b5457b7bdf284d683880163a4c59fdde2f84325a;hp=a667eb1fc26e2dfca7ac7b46b8a93f1eb22867e8;hpb=10b275ddfd05ccb414cfe0cc56a0f47ff20fe807;p=linux-2.6 diff --git a/Documentation/CodingStyle b/Documentation/CodingStyle index a667eb1fc2..7f1730f1a1 100644 --- a/Documentation/CodingStyle +++ b/Documentation/CodingStyle @@ -633,12 +633,27 @@ covers RTL which is used frequently with assembly language in the kernel. Kernel developers like to be seen as literate. Do mind the spelling of kernel messages to make a good impression. Do not use crippled -words like "dont" and use "do not" or "don't" instead. +words like "dont"; use "do not" or "don't" instead. Make the messages +concise, clear, and unambiguous. Kernel messages do not have to be terminated with a period. Printing numbers in parentheses (%d) adds no value and should be avoided. +There are a number of driver model diagnostic macros in +which you should use to make sure messages are matched to the right device +and driver, and are tagged with the right level: dev_err(), dev_warn(), +dev_info(), and so forth. For messages that aren't associated with a +particular device, defines pr_debug() and pr_info(). + +Coming up with good debugging messages can be quite a challenge; and once +you have them, they can be a huge help for remote troubleshooting. Such +messages should be compiled out when the DEBUG symbol is not defined (that +is, by default they are not included). When you use dev_dbg() or pr_debug(), +that's automatic. Many subsystems have Kconfig options to turn on -DDEBUG. +A related convention uses VERBOSE_DEBUG to add dev_vdbg() messages to the +ones already enabled by DEBUG. + Chapter 14: Allocating memory @@ -790,4 +805,5 @@ Kernel CodingStyle, by greg@kroah.com at OLS 2002: http://www.kroah.com/linux/talks/ols_2002_kernel_codingstyle_talk/html/ -- -Last updated on 2006-December-06. +Last updated on 2007-July-13. +