From 36ec19390effc9131132901e8a66a071a7b74a88 Mon Sep 17 00:00:00 2001
From: Joe Perches <joe@perches.com>
Date: Wed, 3 Jul 2013 15:05:25 -0700
Subject: [PATCH] checkpatch: warn on comparisons to jiffies

Comparing jiffies is almost always wrong and time_before and time_after
should be used instead.

Warn on any comparison to jiffies.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 scripts/checkpatch.pl | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 576139a..c274e1d 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3299,6 +3299,12 @@ sub process {
 			}
 		}
 
+# check for comparisons of jiffies
+		if ($line =~ /\bjiffies\s*$Compare|$Compare\s*jiffies\b/) {
+			WARN("JIFFIES_COMPARISON",
+			     "Comparing jiffies is almost always wrong; prefer time_after, time_before and friends\n" . $herecurr);
+		}
+
 # warn about #ifdefs in C files
 #		if ($line =~ /^.\s*\#\s*if(|n)def/ && ($realfile =~ /\.c$/)) {
 #			print "#ifdef in C files should be avoided\n";
-- 
2.7.4