clocksource: Fix bug with max_deferment margin calculation

In order to leave a margin of 12.5% we should >> 3 not >> 5.

CC: stable@kernel.org
Signed-off-by: Yang Honggang (Joseph) <eagle.rtlinux@gmail.com>
[jstultz: Modified commit subject]
Signed-off-by: John Stultz <john.stultz@linaro.org>

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index cfc65e1eb9fbba411fad95fabee1b78f0e6517f3..da2f760e780c9cdf7d1e2b4b02cbf9fffa900cea 100644 (file)
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -548,7 +548,7 @@ 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
@@ -669,7 +669,7 @@ 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)