On 08/01/2013 10:31 AM, Miroslav Lichvar wrote: > The current code requires that the scheduled update of the RTC happens > in the closest tick to the half of the second. This seems to be > difficult to achieve reliably. The scheduled work may be missing the > target time by a tick or two and be constantly rescheduled every second. > > Relax the limit to 10 ticks. As a typical RTC drifts in the 11-minute > update interval by several milliseconds, this shouldn't affect the > overall accuracy of the RTC much. > > Signed-off-by: Miroslav Lichvar <[email protected]> > --- > kernel/time/ntp.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c > index 8f5b3b9..ab1fa7c 100644 > --- a/kernel/time/ntp.c > +++ b/kernel/time/ntp.c > @@ -475,6 +475,7 @@ static void sync_cmos_clock(struct work_struct *work) > * called as close as possible to 500 ms before the new second starts. > * This code is run on a timer. If the clock is set, that timer > * may not expire at the correct time. Thus, we adjust... > + * We want the clock to be within a couple of ticks from the target. > */ > if (!ntp_synced()) { > /* > @@ -485,7 +486,7 @@ static void sync_cmos_clock(struct work_struct *work) > } > > getnstimeofday(&now); > - if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) { > + if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec * 5) { > struct timespec adjust = now; > > fail = -ENODEV;
Applied to my 3.12 branch. thanks -john -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
