Re: [Linuxptp-devel] [PATCH] port: reject negative peer delay in port_peer_delay()

2014-02-18 Thread Richard Cochran
On Wed, Feb 19, 2014 at 12:38:59AM +0100, Holzinger, Axel (ALC NetworX GmbH) wrote: > > So this means using the UDS Interface I guess. But does it really make sense > to use UDS for reading a precise time. Is it fast enough? No, it is not for getting time stamps. For that, you read the PHC dev

Re: [Linuxptp-devel] [PATCH] port: reject negative peer delay in port_peer_delay()

2014-02-18 Thread Holzinger, Axel (ALC NetworX GmbH)
Am Dienstag, 18. Februar 2014 19:21 hat Richard Cochran [richardcoch...@gmail.com] geschrieben: > On Tue, Feb 18, 2014 at 06:29:11PM +0100, Holzinger, Axel (ALC NetworX GmbH) > wrote > > what is the motivation between the different cases (tuning the clock and > > not tuning the clock inPTP/gPTP)

Re: [Linuxptp-devel] [PATCH] port: reject negative peer delay in port_peer_delay()

2014-02-18 Thread Richard Cochran
On Tue, Feb 18, 2014 at 06:29:11PM +0100, Holzinger, Axel (ALC NetworX GmbH) wrote> > what is the motivation between the different cases (tuning the clock and not > tuning the clock in PTP/gPTP). Is this demanded by the standard or good > practice? IEEE 1588 does not tell you how to adjust sl

Re: [Linuxptp-devel] [PATCH] port: reject negative peer delay in port_peer_delay()

2014-02-18 Thread Delio Brignoli
Hello Richard, On 18 Feb 2014, at 16:57, Richard Cochran wrote: > On Wed, Feb 12, 2014 at 09:58:07PM +0100, dbrign...@audioscience.com wrote: >> From: Delio Brignoli >> >> Peer delay should never be negative, when it occurs >> warn the user and drop it. > > I don't think it is right to drop s

Re: [Linuxptp-devel] [PATCH] port: reject negative peer delay in port_peer_delay()

2014-02-18 Thread Holzinger, Axel (ALC NetworX GmbH)
On Tue, February 18, 2014 4:57 PM Richard Cochran wrote: <...> > Even in the gPTP case where you do not tune the clock, still I > would expect that you need the actual peer delay measurement > (even when negative) in order to calculate the true offset > from mast

Re: [Linuxptp-devel] [PATCH] port: reject negative peer delay in port_peer_delay()

2014-02-18 Thread Richard Cochran
On Wed, Feb 12, 2014 at 09:58:07PM +0100, dbrign...@audioscience.com wrote: > From: Delio Brignoli > > Peer delay should never be negative, when it occurs > warn the user and drop it. I don't think it is right to drop such measurements. If the clocks are far enough apart in frequency and the res