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Error "clock jumped backward or running slower than expected!" #10
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Hi John, |
Great thanks, Vladmir
However, if I keep repeated to modifying the time between 1500002055 and 1595964364 many times, So looks like there is some corner case... P.S This problem never happens with ptp4l (version2.0) running on my Linux PC(I210). John |
What is the maximum frequency adjustment in parts per billion for enetc, and what is it for i210?
If the max freq adjustment for i210 is below the default sanity frequency limit value of 200000000, then that's your answer. |
Hi Vladimir,
Thank you for your reply.
On 2020/07/29 17:25, Vladimir Oltean wrote:
What is the maximum frequency adjustment in parts per billion for enetc, and what is it for i210?
./testptp -c -d /dev/ptp0
capabilities:
999999999 maximum frequency adjustment (ppb)
0 programmable alarms
2 external time stamp channels
0 programmable periodic signals
1 pulse per second
0 programmable pins
0 cross timestamping
0 adjust_phase
#LS1028ARDB
$./testptp -c
capabilities:
999999999 maximum frequency adjustment (ppb)
0 programmable alarms
2 external time stamp channels
0 programmable periodic signals
1 pulse per second
0 programmable pins
0 cross timestamping
#Linux PC (I210)
$testptp -c -d /dev/ptp1
capabilities:
62499999 maximum frequency adjustment (ppb)
0 programmable alarms
2 external time stamp channels
2 programmable periodic signals
1 pulse per second
4 programmable pins
0 cross timestamping
If the max freq adjustment for i210 is below the default sanity frequency limit value of 200000000, then that's your answer.
Yes, the max freq adjustment for I210 is 62499999, which is below 200000000.
So, with enetc, what happens if you configure |max_frequency| and |sanity_freq_limit| both to 999999999?
It'll no longer complain, that's for sure, but the question is: will it work?
Setting the 999999999 to both max_frequency and sanity_freq_limit resulted in the same problem.
Using the same number with I210(max_frequency to 62499999 and sanity_freq_limit to 200000000) resulted in the problem fixed.
(at least I never see the problem so far.) $testptp -g always return the synced time.
I'm curious what was the root cause of this problem(who was wrong anyway ?? Changing GM time so much is not allowed ??),
so I read the man page of ptp for the parameter explanation, and tried to understand the code, but coding of frequency
check part of linuxptp is little bit complicated to me to understand the mechanism in a short time.
So if you or someone could explain a little bit more, it's really appreciated.
But at least problem was fixed. So thank you very much !!
John
|
hello, i change my param from 999999999 to 62499999 on my slave device, the erros message is missing, but the ptp can not sync time from master? |
Environment
LS1028ARDB
SW
network setup
Problem
How to duplicate
$ptp4l -i eno0 -p /dev/ptp0 -f /etc/ptp4l_cfg/gPTP.cfg -m -l 7 |& tee tmp.log
clock time: 1500002055.106458152 or Thu Jul 13 23:14:15 2017
Problem
(Following command result is not changed to 1595964364)
clock time: 1500002055.106458152 or Thu Jul 13 23:14:15 2017
ptp4l[521866.541]: clockcheck: clock jumped backward or running slower than expected!
Would you please help on this ?
Thanks !!
John
tmp.log
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