[PATCH 1/1] clocksource: In order to leave a margin of 12.5% we should >> 3 not >> 5.

From: Yang Honggang (Joseph)
Date: Thu Dec 01 2011 - 09:22:15 EST



Signed-off-by: Yang Honggang (Joseph) <eagle.rtlinux@xxxxxxxxx>
---
kernel/time/clocksource.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index cf52fda..b9bf9d0 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -529,7 +529,7 @@ static u64 clocksource_max_deferment(struct clocksource *cs)
* note a margin of 12.5% is used because this can be computed with
* a shift, versus say 10% which would require division.
*/
- return max_nsecs - (max_nsecs >> 5);
+ return max_nsecs - (max_nsecs >> 3);
}

#ifndef CONFIG_ARCH_USES_GETTIMEOFFSET
@@ -651,7 +651,7 @@ void __clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq)
* ~ 0.06ppm granularity for NTP. We apply the same 12.5%
* margin as we do in clocksource_max_deferment()
*/
- sec = (cs->mask - (cs->mask >> 5));
+ sec = (cs->mask - (cs->mask >> 3));
do_div(sec, freq);
do_div(sec, scale);
if (!sec)
--
1.7.2.5

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