add a trivial patch style checker

We are seeing increasing levels of minor patch style violations in submissions
to the mailing lists as well as making it into the tree.  These detract from
the quality of the submission and cause unnessary work for reviewers.

As a first step package up the current state of the patch style checker and
include it in the kernel tree.  Add instructions suggesting running it on
submissions.  This adds version v0.01 of the checkpatch.pl script.

Signed-off-by: Andy Whitcroft <[email protected]>
Signed-off-by: Joel Schopp <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Dave Jones <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Documentation/SubmitChecklist

@@ -84,3 +84,9 @@ kernel patches.
 24: Avoid whitespace damage such as indenting with spaces or whitespace
     at the end of lines.  You can test this by feeding the patch to
     "git apply --check --whitespace=error-all"
+
+25: Check your patch for general style as detailed in
+    Documentation/CodingStyle.  Check for trivial violations with the
+    patch style checker prior to submission (scripts/checkpatch.pl).
+    You should be able to justify all violations that remain in
+    your patch.

Documentation/SubmittingPatches

@@ -118,7 +118,20 @@ then only post say 15 or so at a time and wait for review and integration.
 
 
 
-4) Select e-mail destination.
+4) Style check your changes.
+
+Check your patch for basic style violations, details of which can be
+found in Documentation/CodingStyle.  Failure to do so simply wastes
+the reviewers time and will get your patch rejected, probabally
+without even being read.
+
+At a minimum you should check your patches with the patch style
+checker prior to submission (scripts/patchcheck.pl).  You should
+be able to justify all violations that remain in your patch.
+
+
+
+5) Select e-mail destination.
 
 Look through the MAINTAINERS file and the source code, and determine
 if your change applies to a specific subsystem of the kernel, with
@@ -146,7 +159,7 @@ discussed should the patch then be submitted to Linus.
 
 
 
-5) Select your CC (e-mail carbon copy) list.
+6) Select your CC (e-mail carbon copy) list.
 
 Unless you have a reason NOT to do so, CC [email protected].
 
@@ -187,8 +200,7 @@ URL: <http://www.kernel.org/pub/linux/kernel/people/bunk/trivial/>
 
 
 
-
-6) No MIME, no links, no compression, no attachments.  Just plain text.
+7) No MIME, no links, no compression, no attachments.  Just plain text.
 
 Linus and other kernel developers need to be able to read and comment
 on the changes you are submitting.  It is important for a kernel
@@ -223,9 +235,9 @@ pref("mailnews.display.disable_format_flowed_support", true);
 
 
 
-7) E-mail size.
+8) E-mail size.
 
-When sending patches to Linus, always follow step #6.
+When sending patches to Linus, always follow step #7.
 
 Large changes are not appropriate for mailing lists, and some
 maintainers.  If your patch, uncompressed, exceeds 40 kB in size,
@@ -234,7 +246,7 @@ server, and provide instead a URL (link) pointing to your patch.
 
 
 
-8) Name your kernel version.
+9) Name your kernel version.
 
 It is important to note, either in the subject line or in the patch
 description, the kernel version to which this patch applies.
@@ -244,7 +256,7 @@ Linus will not apply it.
 
 
 
-9) Don't get discouraged.  Re-submit.
+10) Don't get discouraged.  Re-submit.
 
 After you have submitted your change, be patient and wait.  If Linus
 likes your change and applies it, it will appear in the next version
@@ -270,7 +282,7 @@ When in doubt, solicit comments on linux-kernel mailing list.
 
 
 
-10) Include PATCH in the subject
+11) Include PATCH in the subject
 
 Due to high e-mail traffic to Linus, and to linux-kernel, it is common
 convention to prefix your subject line with [PATCH].  This lets Linus
@@ -279,7 +291,7 @@ e-mail discussions.
 
 
 
-11) Sign your work
+12) Sign your work
 
 To improve tracking of who did what, especially with patches that can
 percolate to their final resting place in the kernel through several
@@ -328,7 +340,8 @@ now, but you can do this to mark internal company procedures or just
 point out some special detail about the sign-off. 
 
 
-12) The canonical patch format
+
+13) The canonical patch format
 
 The canonical patch subject line is:
 
@@ -427,6 +440,10 @@ section Linus Computer Science 101.
 Nuff said.  If your code deviates too much from this, it is likely
 to be rejected without further review, and without comment.
 
+Check your patches with the patch style checker prior to submission
+(scripts/checkpatch.pl).  You should be able to justify all
+violations that remain in your patch.
+
 
 
 2) #ifdefs are ugly

Documentation/feature-removal-schedule.txt

@@ -70,6 +70,7 @@ Who:	David Miller <[email protected]>
 
 What:	Video4Linux API 1 ioctls and video_decoder.h from Video devices.
 When:	December 2006
+Files:	include/linux/video_decoder.h
 Why:	V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
 	series. The old API have lots of drawbacks and don't provide enough
 	means to work with all video and audio standards. The newer API is

MAINTAINERS

@@ -30,8 +30,11 @@ trivial patch so apply some common sense.
 	job the maintainers (and especially Linus) do is to keep things
 	looking the same. Sometimes this means that the clever hack in
 	your driver to get around a problem actually needs to become a
-	generalized kernel feature ready for next time. See
-	Documentation/CodingStyle for guidance here.
+	generalized kernel feature ready for next time.
+
+	PLEASE check your patch with the automated style checker
+	(scripts/checkpatch.pl) to catch trival style violations.
+	See Documentation/CodingStyle for guidance here.
 
 	PLEASE try to include any credit lines you want added with the
 	patch. It avoids people being missed off by mistake and makes
@@ -972,6 +975,15 @@ M:	[email protected]
 L:	[email protected]
 S:	Maintained
 
+CHECKPATCH
+P:	Andy Whitcroft
+M:	[email protected]
+P:	Randy Dunlap
+M:	[email protected]
+P:	Joel Schopp
+M:	[email protected]
+S:	Supported
+
 COMMON INTERNET FILE SYSTEM (CIFS)
 P:	Steve French
 M:	[email protected]