Messages in this thread | | | Date | Mon, 6 Jul 2015 15:44:58 -0500 | From | Josh Cartwright <> | Subject | Re: [PATCH v2 1/1] Added additional callback to ptp_clock_info: |
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On Thu, Jul 02, 2015 at 06:14:48PM -0700, Christopher Hall wrote: > * getsynctime64()
Hello Christopher-
A couple comments below.
> > This takes 2 arguments referring to system and device time > > With this callback drivers may provide both system time and device time > to ensure precise correlation > > Modified PTP_SYS_OFFSET ioctl in PTP clock driver to use the above > callback if it's available > > Added capability (PTP_CLOCK_GETCAPS) for checking whether driver supports > precise timestamping > > Signed-off-by: Christopher Hall <christopher.s.hall@intel.com> > --- [..] > @@ -196,19 +197,31 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) > break; > } > pct = &sysoff->ts[0]; > - for (i = 0; i < sysoff->n_samples; i++) { > - getnstimeofday64(&ts); > + if (ptp->info->getsynctime64 && sysoff->n_samples == 1) { > + ptp->info->getsynctime64(ptp->info, &ts, &systs); > + pct->sec = systs.tv_sec; > + pct->nsec = systs.tv_nsec;
It's difficult to make too many judgements without seeing how a driver might implement this; is there another patchset that shows how a driver implements this?
[..] > diff --git a/include/uapi/linux/ptp_clock.h b/include/uapi/linux/ptp_clock.h > index f0b7bfe..421b637 100644 > --- a/include/uapi/linux/ptp_clock.h > +++ b/include/uapi/linux/ptp_clock.h > @@ -51,7 +51,9 @@ struct ptp_clock_caps { > int n_per_out; /* Number of programmable periodic signals. */ > int pps; /* Whether the clock supports a PPS callback. */ > int n_pins; /* Number of input/output pins. */ > - int rsv[14]; /* Reserved for future use. */ > + /* Whether the clock supports precise system-device cross timestamps */ > + int precise_timestamping;
Perhaps now is a good time to add an unsigned int 'flags' member instead, and start allocating bits.
Josh [unhandled content-type:application/pgp-signature] | |