Messages in this thread | | | Date | Mon, 23 Jan 2017 19:44:15 +0100 | From | Richard Cochran <> | Subject | Re: [patch 4/5] PTP: add PTP_SYS_OFFSET emulation via cross timestamps infrastructure |
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On Mon, Jan 23, 2017 at 11:19:17AM -0200, Marcelo Tosatti wrote: > This is needed to generate the PTP_SYS_OFFSET data: a table with read > from realtime clock, read from device clock, read from realtime clock, > ... : > > time -> > device clock | |sample2| |sample4| |sample6| ... > ------------------------------------------------------------- > realtime clock |sample1| |sample3| |sample5|
Here "realtime clock" is CLOCK_REALTIME on the guest, and "device clock" is CLOCK_REALTIME on the host?
> Where sampleN is the read of the respective clock. > > From the following PTP_SYS_OFFSET_PRECISE data: > > device clock |sample1P,deviceclock| |sample2P,deviceclock| > ------------------------------------------------------------- > realtime clock |sample1P,realtimeclock| |sample2P,realtimeclock|
Are |sample1P,deviceclock| and |sample1P,realtimeclock| taken at the same instant in time?
If not, then calling that PTP_SYS_OFFSET_PRECISE is misleading.
Still don't get what you are doing here...
Thanks, Richard
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