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authorPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>2006-12-07 02:14:07 +0100
committerAndi Kleen <andi@basil.nowhere.org>2006-12-07 02:14:07 +0100
commitb9a8d94a47f8a41766f6f7944adfb1d641349903 (patch)
tree906fa09322f59c60132ff898e212f49a7d9a555e
parentbff6547bb6a4e82c399d74e7fba78b12d2f162ed (diff)
[PATCH] x86-64: Make x86_64 udelay() round up instead of down.
Port two patches from i386 to x86_64 delay.c to make sure all rounding is done upward instead of downward. There is no sign in commit messages that the mismatch was done on purpose, and "delay() guarantees sleeping at least for the specified time" is still a valid rule IMHO. The original x86 patches are both from pre-GIT era, i.e.: "[PATCH] round up in __udelay()" in commit 54c7e1f5cc6771ff644d7bc21a2b829308bd126f "[PATCH] add 1 in __const_udelay()" in commit 42c77a9801b8877d8b90f65f75db758822a0bccc (both commits are from converted BK repository to x86_64). AK: fixed gcc warning linux/arch/x86_64/lib/delay.c:43: warning: suggest parentheses around + or - inside shift (did this actually work?) Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andi Kleen <ak@suse.de>
-rw-r--r--arch/x86_64/lib/delay.c4
-rw-r--r--include/asm-x86_64/delay.h2
2 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86_64/lib/delay.c b/arch/x86_64/lib/delay.c
index 50be90975d0..2dbebd30834 100644
--- a/arch/x86_64/lib/delay.c
+++ b/arch/x86_64/lib/delay.c
@@ -40,13 +40,13 @@ EXPORT_SYMBOL(__delay);
inline void __const_udelay(unsigned long xloops)
{
- __delay((xloops * HZ * cpu_data[raw_smp_processor_id()].loops_per_jiffy) >> 32);
+ __delay(((xloops * HZ * cpu_data[raw_smp_processor_id()].loops_per_jiffy) >> 32) + 1);
}
EXPORT_SYMBOL(__const_udelay);
void __udelay(unsigned long usecs)
{
- __const_udelay(usecs * 0x000010c6); /* 2**32 / 1000000 */
+ __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
}
EXPORT_SYMBOL(__udelay);
diff --git a/include/asm-x86_64/delay.h b/include/asm-x86_64/delay.h
index 65f64acc531..40146f611cc 100644
--- a/include/asm-x86_64/delay.h
+++ b/include/asm-x86_64/delay.h
@@ -16,7 +16,7 @@ extern void __const_udelay(unsigned long usecs);
extern void __delay(unsigned long loops);
#define udelay(n) (__builtin_constant_p(n) ? \
- ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c6ul)) : \
+ ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c7ul)) : \
__udelay(n))
#define ndelay(n) (__builtin_constant_p(n) ? \