Commit 43c1d77c authored by Joe Perches's avatar Joe Perches Committed by Linus Torvalds

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 $herecurr.
Signed-off-by: default avatarJoe Perches <joe@perches.com>
Reported-by: default avatarHolger Schurig <holgerschurig@gmail.com>
Cc: Sujith Manoharan <sujith@msujith.org>
Cc: John Linville <linville@tuxdriver.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent af661e83
......@@ -3912,10 +3912,15 @@ sub process {
# prefer usleep_range over udelay
if ($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);
}
}
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment