checkpatch: add test for long udelay
Holger reported:
: The macro udelay cannot handle large values because of loss-of-precision.
:
: IMHO udelay on ARM is broken, because it also cannot work with fast
: ARM processors (where bogomips >= 3355, which is in sight now). It's
: just not broken enough that someone did something against it ... so
: the current kludge is good enough.
Until then, warn on long udelay uses.
Also fix uses of $line that should have been $herecurr.
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Holger Schurig <holgerschurig@gmail.com>
Cc: Sujith Manoharan <sujith@msujith.org>
Cc: John Linville <linville@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 464dcef..7d3bc2f 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3912,10 +3912,15 @@
# prefer usleep_range over udelay
if ($line =~ /\budelay\s*\(\s*(\d+)\s*\)/) {
+ my $delay = $1;
# ignore udelay's < 10, however
- if (! ($1 < 10) ) {
+ if (! ($delay < 10) ) {
CHK("USLEEP_RANGE",
- "usleep_range is preferred over udelay; see Documentation/timers/timers-howto.txt\n" . $line);
+ "usleep_range is preferred over udelay; see Documentation/timers/timers-howto.txt\n" . $herecurr);
+ }
+ if ($delay > 2000) {
+ WARN("LONG_UDELAY",
+ "long udelay - prefer mdelay; see arch/arm/include/asm/delay.h\n" . $herecurr);
}
}
@@ -3923,7 +3928,7 @@
if ($line =~ /\bmsleep\s*\((\d+)\);/) {
if ($1 < 20) {
WARN("MSLEEP",
- "msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt\n" . $line);
+ "msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt\n" . $herecurr);
}
}
