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authorJoe Perches <joe@perches.com>2014-04-03 14:49:11 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-03 16:21:12 -0700
commit43c1d77c393205645cdd6337e657341a5216a7a8 (patch)
tree32d46fe129f6be4b2a225e381617ab2e0ce082ed
parentaf661e836039cbc2aadb3bccfd7d3ddfc1bcc456 (diff)
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 $herecurr. Signed-off-by: Joe Perches <joe@perches.com> Reported-by: Holger Schurig <holgerschurig@gmail.com> Cc: Sujith Manoharan <sujith@msujith.org> Cc: John Linville <linville@tuxdriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rwxr-xr-xscripts/checkpatch.pl11
1 files changed, 8 insertions, 3 deletions
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 464dcef79b35..7d3bc2f3c326 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3912,10 +3912,15 @@ sub process {
# prefer usleep_range over udelay
if ($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" . $herecurr);
}
}
@@ -3923,7 +3928,7 @@ sub process {
if ($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);
}
}