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| author | Paolo 'Blaisorblade' Giarrusso | 2006-12-07 02:14:07 +0100 |
|---|---|---|
| committer | Andi Kleen | 2006-12-07 02:14:07 +0100 |
| commit | e6536c1262c56d302e749ab1b44fdb0b9786327d (patch) | |
| tree | 6463b5c2eb8b156a6fcfffa283a803c0f8a8949b /include/asm-x86_64/delay.h | |
| parent | [PATCH] x86-64: Make x86_64 udelay() round up instead of down. (diff) | |
| download | kernel-qcow2-linux-e6536c1262c56d302e749ab1b44fdb0b9786327d.tar.gz kernel-qcow2-linux-e6536c1262c56d302e749ab1b44fdb0b9786327d.tar.xz kernel-qcow2-linux-e6536c1262c56d302e749ab1b44fdb0b9786327d.zip | |
[PATCH] x86: comment magic constants in delay.h
For both i386 and x86_64, copy from arch/$ARCH/lib/delay.c comments about the
used magic constants, plus a few other niceties.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andi Kleen <ak@suse.de>
include/asm-i386/delay.h | 5 ++++-
include/asm-x86_64/delay.h | 5 ++++-
2 files changed, 8 insertions(+), 2 deletions(-)
Diffstat (limited to 'include/asm-x86_64/delay.h')
| -rw-r--r-- | include/asm-x86_64/delay.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/asm-x86_64/delay.h b/include/asm-x86_64/delay.h index 40146f611ccb..c2669f1f5529 100644 --- a/include/asm-x86_64/delay.h +++ b/include/asm-x86_64/delay.h @@ -7,18 +7,21 @@ * Delay routines calling functions in arch/x86_64/lib/delay.c */ +/* Undefined functions to get compile-time errors */ extern void __bad_udelay(void); extern void __bad_ndelay(void); extern void __udelay(unsigned long usecs); -extern void __ndelay(unsigned long usecs); +extern void __ndelay(unsigned long nsecs); extern void __const_udelay(unsigned long usecs); extern void __delay(unsigned long loops); +/* 0x10c7 is 2**32 / 1000000 (rounded up) */ #define udelay(n) (__builtin_constant_p(n) ? \ ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c7ul)) : \ __udelay(n)) +/* 0x5 is 2**32 / 1000000000 (rounded up) */ #define ndelay(n) (__builtin_constant_p(n) ? \ ((n) > 20000 ? __bad_ndelay() : __const_udelay((n) * 5ul)) : \ __ndelay(n)) |