From 43c1d77c393205645cdd6337e657341a5216a7a8 Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Thu, 3 Apr 2014 14:49:11 -0700 Subject: [PATCH] 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 $herecurr. Signed-off-by: Joe Perches Reported-by: Holger Schurig Cc: Sujith Manoharan Cc: John Linville Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- scripts/checkpatch.pl | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 464dcef79b35..7d3bc2f3c326 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -3912,10 +3912,15 @@ sub process { # prefer usleep_range over udelay if ($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); } } -- 2.20.1