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    SubjectRe: [PATCHv2 3/6] pps: capture MONOTONIC_RAW timestamps as well
    On Wed, Feb 24, 2010 at 03:28:14PM +0300, Alexander Gordeev wrote:
    > MONOTONIC_RAW clock timestamps are ideally suited for frequency
    > calculation and also fit well into the original NTP hardpps design. Now
    > phase and frequency can be adjusted separately: the former based on
    > REALTIME clock and the latter based on MONOTONIC_RAW clock.
    > A new function getnstime_raw_and_real is added to timekeeping subsystem
    > to capture both timestamps at the same time and atomically.
    >
    > Signed-off-by: Alexander Gordeev <lasaine@lvk.cs.msu.su>

    Acked-by: Rodolfo Giometti <giometti@linux.it>

    > ---
    > include/linux/pps_kernel.h | 3 ++-
    > include/linux/time.h | 2 ++
    > kernel/time/timekeeping.c | 34 ++++++++++++++++++++++++++++++++++
    > 3 files changed, 38 insertions(+), 1 deletions(-)
    >
    > diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h
    > index a2804c1..9bda892 100644
    > --- a/include/linux/pps_kernel.h
    > +++ b/include/linux/pps_kernel.h
    > @@ -41,6 +41,7 @@ struct pps_source_info {
    > };
    >
    > struct pps_event_time {
    > + struct timespec ts_raw;
    > struct pps_ktime ts_real;
    > };
    >
    > @@ -104,7 +105,7 @@ static inline void pps_get_ts(struct pps_event_time *ts)
    > {
    > struct timespec ts_real;
    >
    > - getnstimeofday(&ts_real);
    > + getnstime_raw_and_real(&ts->ts_raw, &ts_real);
    > timespec_to_pps_ktime(&ts->ts_real, ts_real);
    > }
    >
    > diff --git a/include/linux/time.h b/include/linux/time.h
    > index 6e026e4..edf7eb7 100644
    > --- a/include/linux/time.h
    > +++ b/include/linux/time.h
    > @@ -143,6 +143,8 @@ extern unsigned int alarm_setitimer(unsigned int seconds);
    > extern int do_getitimer(int which, struct itimerval *value);
    > extern void getnstimeofday(struct timespec *tv);
    > extern void getrawmonotonic(struct timespec *ts);
    > +extern void getnstime_raw_and_real(struct timespec *ts_raw,
    > + struct timespec *ts_real);
    > extern void getboottime(struct timespec *ts);
    > extern void monotonic_to_bootbased(struct timespec *ts);
    >
    > diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
    > index 8b709de..0ca8336 100644
    > --- a/kernel/time/timekeeping.c
    > +++ b/kernel/time/timekeeping.c
    > @@ -293,6 +293,40 @@ void ktime_get_ts(struct timespec *ts)
    > EXPORT_SYMBOL_GPL(ktime_get_ts);
    >
    > /**
    > + * getnstime_raw_and_real - Returns both the time of day an raw
    > + * monotonic time in a timespec format
    > + * @ts_mono_raw: pointer to the timespec to be set to raw
    > + * monotonic time
    > + * @ts_real: pointer to the timespec to be set to the time
    > + * of day
    > + */
    > +void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
    > +{
    > + unsigned long seq;
    > + s64 nsecs_raw, nsecs_real;
    > +
    > + WARN_ON(timekeeping_suspended);
    > +
    > + do {
    > + seq = read_seqbegin(&xtime_lock);
    > +
    > + *ts_raw = raw_time;
    > + *ts_real = xtime;
    > +
    > + nsecs_raw = timekeeping_get_ns_raw();
    > + nsecs_real = timekeeping_get_ns();
    > +
    > + /* If arch requires, add in gettimeoffset() */
    > + nsecs_real += arch_gettimeoffset();
    > +
    > + } while (read_seqretry(&xtime_lock, seq));
    > +
    > + timespec_add_ns(ts_raw, nsecs_raw);
    > + timespec_add_ns(ts_real, nsecs_real);
    > +}
    > +EXPORT_SYMBOL(getnstime_raw_and_real);
    > +
    > +/**
    > * do_gettimeofday - Returns the time of day in a timeval
    > * @tv: pointer to the timeval to be set
    > *
    > --
    > 1.6.6.1
    >

    --

    GNU/Linux Solutions e-mail: giometti@enneenne.com
    Linux Device Driver giometti@linux.it
    Embedded Systems phone: +39 349 2432127
    UNIX programming skype: rodolfo.giometti
    Freelance ICT Italia - Consulente ICT Italia - www.consulenti-ict.it


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