Re: [PATCH v3 3/4] Add support for driver cross-timestamp to PTP_SYS_OFFSET ioctl

From	Richard Cochran <richardcochran@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v3 3/4] Add support for driver cross-timestamp to PTP_SYS_OFFSET ioctl
Date	2015-08-23 13:30 +0200
Message-ID	<q0BDk-7OP-17@gated-at.bofh.it> (permalink)
References	<q06ga-4Gw-3@gated-at.bofh.it> <q06ga-4Gw-11@gated-at.bofh.it> <q0nK1-4zp-5@gated-at.bofh.it> <q0omJ-5Ao-1@gated-at.bofh.it> <q0yFs-3AK-13@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Sun, Aug 23, 2015 at 10:15:00AM +0200, Thomas Gleixner wrote:
> So why can't you take N samples from the synced hardware? It does not
> make any sense to me to switch to the imprecise mode if nsamples > 1.

Ok, then I prefer to leave this "imprecise" method in place and ...
 
> You can also provide a new IOCTL PTP_SYS_OFFSET_PRECISE which returns
> -ENOSYS if hardware timestamping is not available and avoid the whole
> nsamples dance for the case where we can get precise timestamps.

have this for the new way.

By keeping the imprecise method, we will be able to run both methods
on the new hardware.  That will help to quantify how imprecise the old
method is.

Thanks,
Richard

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Thread

[PATCH v3 3/4] Add support for driver cross-timestamp to PTP_SYS_OFFSET ioctl "Christopher S. Hall" <christopher.s.hall@intel.com> - 2015-08-22 04:00 +0200
  Re: [PATCH v3 3/4] Add support for driver cross-timestamp to  PTP_SYS_OFFSET ioctl Thomas Gleixner <tglx@linutronix.de> - 2015-08-22 22:40 +0200
    Re: [PATCH v3 3/4] Add support for driver cross-timestamp to  PTP_SYS_OFFSET ioctl Richard Cochran <richardcochran@gmail.com> - 2015-08-22 23:20 +0200
      Re: [PATCH v3 3/4] Add support for driver cross-timestamp to  PTP_SYS_OFFSET ioctl Thomas Gleixner <tglx@linutronix.de> - 2015-08-23 10:20 +0200
        Re: [PATCH v3 3/4] Add support for driver cross-timestamp to  PTP_SYS_OFFSET ioctl Richard Cochran <richardcochran@gmail.com> - 2015-08-23 13:30 +0200
          RE: [PATCH v3 3/4] Add support for driver cross-timestamp to  PTP_SYS_OFFSET ioctl "Hall, Christopher S" <christopher.s.hall@intel.com> - 2015-08-24 22:20 +0200
            Re: [PATCH v3 3/4] Add support for driver cross-timestamp to  PTP_SYS_OFFSET ioctl Richard Cochran <richardcochran@gmail.com> - 2015-08-25 09:40 +0200

csiph-web