Discussion:
[Linuxptp-users] E2E Protocol
Hardik Gohil
2017-01-13 01:40:45 UTC
Permalink
Hello,

I am working on Linux 3.12 running on TI AM335x.

The Test system is GPS connected to CPU over Ethernet and GPS is configured
to End to End protocol.

following are the messages
--------------------------------------
ptp4l[71468.231]: master offset -230 s2 freq -23449 path delay
15359
ptp4l[71469.232]: master offset -185 s2 freq -23473 path delay
15372
ptp4l[71470.233]: master offset 90 s2 freq -23254 path delay
15503
ptp4l[71471.234]: master offset -321 s2 freq -23638 path delay
15500
ptp4l[71472.234]: master offset 152 s2 freq -23261 path delay
15500
ptp4l[71473.235]: master offset 279 s2 freq -23088 path delay
15500
ptp4l[71474.237]: master offset -343 s2 freq -23627 path delay
15500
ptp4l[71475.242]: master offset 77 s2 freq -23310 path delay
15500
ptp4l[71476.242]: master offset 51 s2 freq -23313 path delay
15500
ptp4l[71477.242]: master offset 29 s2 freq -23319 path delay
15500
-----------------------------------------
phc2sys[71501.627]: sys offset -75 s2 freq -23336 delay 3480
phc2sys[71502.628]: sys offset 37 s2 freq -23246 delay 3521
phc2sys[71503.629]: sys offset 229 s2 freq -23043 delay 3480
phc2sys[71504.630]: sys offset -3 s2 freq -23207 delay 3560
phc2sys[71505.631]: sys offset -203 s2 freq -23408 delay 3520
phc2sys[71506.631]: sys offset -340 s2 freq -23605 delay 3440
phc2sys[71507.632]: sys offset -233 s2 freq -23600 delay 3560
phc2sys[71508.633]: sys offset -8 s2 freq -23445 delay 3480
phc2sys[71509.634]: sys offset 234 s2 freq -23206 delay 3521
phc2sys[71510.634]: sys offset 235 s2 freq -23135 delay 3560
phc2sys[71511.635]: sys offset 162 s2 freq -23137 delay 3520
phc2sys[71512.636]: sys offset 37 s2 freq -23213 delay 3520
phc2sys[71513.637]: sys offset -252 s2 freq -23491 delay 3560
phc2sys[71514.638]: sys offset -89 s2 freq -23404 delay 3560
phc2sys[71515.639]: sys offset 269 s2 freq -23073 delay 3480
----------------------------------------------

I am trying to understand this messages.

how do I know whether system time is synced to GPS and what is accuracy ??




Regards,
Hardik A Gohil
Dale Smith
2017-01-13 03:23:36 UTC
Permalink
Offset and Delay are in nanoseconds. The Frequency is (I'm pretty
sure) in parts-per billion.

-Dale
Post by Hardik Gohil
Hello,
I am working on Linux 3.12 running on TI AM335x.
The Test system is GPS connected to CPU over Ethernet and GPS is configured
to End to End protocol.
following are the messages
--------------------------------------
ptp4l[71468.231]: master offset -230 s2 freq -23449 path delay
15359
ptp4l[71469.232]: master offset -185 s2 freq -23473 path delay
15372
ptp4l[71470.233]: master offset 90 s2 freq -23254 path delay
15503
ptp4l[71471.234]: master offset -321 s2 freq -23638 path delay
15500
ptp4l[71472.234]: master offset 152 s2 freq -23261 path delay
15500
ptp4l[71473.235]: master offset 279 s2 freq -23088 path delay
15500
ptp4l[71474.237]: master offset -343 s2 freq -23627 path delay
15500
ptp4l[71475.242]: master offset 77 s2 freq -23310 path delay
15500
ptp4l[71476.242]: master offset 51 s2 freq -23313 path delay
15500
ptp4l[71477.242]: master offset 29 s2 freq -23319 path delay
15500
-----------------------------------------
phc2sys[71501.627]: sys offset -75 s2 freq -23336 delay 3480
phc2sys[71502.628]: sys offset 37 s2 freq -23246 delay 3521
phc2sys[71503.629]: sys offset 229 s2 freq -23043 delay 3480
phc2sys[71504.630]: sys offset -3 s2 freq -23207 delay 3560
phc2sys[71505.631]: sys offset -203 s2 freq -23408 delay 3520
phc2sys[71506.631]: sys offset -340 s2 freq -23605 delay 3440
phc2sys[71507.632]: sys offset -233 s2 freq -23600 delay 3560
phc2sys[71508.633]: sys offset -8 s2 freq -23445 delay 3480
phc2sys[71509.634]: sys offset 234 s2 freq -23206 delay 3521
phc2sys[71510.634]: sys offset 235 s2 freq -23135 delay 3560
phc2sys[71511.635]: sys offset 162 s2 freq -23137 delay 3520
phc2sys[71512.636]: sys offset 37 s2 freq -23213 delay 3520
phc2sys[71513.637]: sys offset -252 s2 freq -23491 delay 3560
phc2sys[71514.638]: sys offset -89 s2 freq -23404 delay 3560
phc2sys[71515.639]: sys offset 269 s2 freq -23073 delay 3480
----------------------------------------------
I am trying to understand this messages.
how do I know whether system time is synced to GPS and what is accuracy ??
Regards,
Hardik A Gohil
------------------------------------------------------------------------------
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Access to Intel Xeon Phi processor-based developer platforms.
With one year of Intel Parallel Studio XE.
Training and support from Colfax.
Order your platform today. http://sdm.link/xeonphi
_______________________________________________
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Dale Smith
2017-01-13 03:25:00 UTC
Permalink
On Thu, Jan 12, 2017 at 10:23 PM, Dale Smith
Apologies for top-posting... Too quick with the send.

-Dale
Hardik Gohil
2017-01-13 07:31:14 UTC
Permalink
I would like to know the accuracy of time synchronization ?

And the difference between path delay and master offset ?

the value of master offset is the accuracy value ?



Regards,
Hardik A Gohil
Post by Dale Smith
Offset and Delay are in nanoseconds. The Frequency is (I'm pretty
sure) in parts-per billion.
-Dale
Post by Hardik Gohil
Hello,
I am working on Linux 3.12 running on TI AM335x.
The Test system is GPS connected to CPU over Ethernet and GPS is
configured
Post by Hardik Gohil
to End to End protocol.
following are the messages
--------------------------------------
ptp4l[71468.231]: master offset -230 s2 freq -23449 path delay
15359
ptp4l[71469.232]: master offset -185 s2 freq -23473 path delay
15372
ptp4l[71470.233]: master offset 90 s2 freq -23254 path delay
15503
ptp4l[71471.234]: master offset -321 s2 freq -23638 path delay
15500
ptp4l[71472.234]: master offset 152 s2 freq -23261 path delay
15500
ptp4l[71473.235]: master offset 279 s2 freq -23088 path delay
15500
ptp4l[71474.237]: master offset -343 s2 freq -23627 path delay
15500
ptp4l[71475.242]: master offset 77 s2 freq -23310 path delay
15500
ptp4l[71476.242]: master offset 51 s2 freq -23313 path delay
15500
ptp4l[71477.242]: master offset 29 s2 freq -23319 path delay
15500
-----------------------------------------
phc2sys[71501.627]: sys offset -75 s2 freq -23336 delay 3480
phc2sys[71502.628]: sys offset 37 s2 freq -23246 delay 3521
phc2sys[71503.629]: sys offset 229 s2 freq -23043 delay 3480
phc2sys[71504.630]: sys offset -3 s2 freq -23207 delay 3560
phc2sys[71505.631]: sys offset -203 s2 freq -23408 delay 3520
phc2sys[71506.631]: sys offset -340 s2 freq -23605 delay 3440
phc2sys[71507.632]: sys offset -233 s2 freq -23600 delay 3560
phc2sys[71508.633]: sys offset -8 s2 freq -23445 delay 3480
phc2sys[71509.634]: sys offset 234 s2 freq -23206 delay 3521
phc2sys[71510.634]: sys offset 235 s2 freq -23135 delay 3560
phc2sys[71511.635]: sys offset 162 s2 freq -23137 delay 3520
phc2sys[71512.636]: sys offset 37 s2 freq -23213 delay 3520
phc2sys[71513.637]: sys offset -252 s2 freq -23491 delay 3560
phc2sys[71514.638]: sys offset -89 s2 freq -23404 delay 3560
phc2sys[71515.639]: sys offset 269 s2 freq -23073 delay 3480
----------------------------------------------
I am trying to understand this messages.
how do I know whether system time is synced to GPS and what is accuracy
??
Post by Hardik Gohil
Regards,
Hardik A Gohil
------------------------------------------------------------
------------------
Post by Hardik Gohil
Developer Access Program for Intel Xeon Phi Processors
Access to Intel Xeon Phi processor-based developer platforms.
With one year of Intel Parallel Studio XE.
Training and support from Colfax.
Order your platform today. http://sdm.link/xeonphi
_______________________________________________
Linuxptp-users mailing list
https://lists.sourceforge.net/lists/listinfo/linuxptp-users
Richard Cochran
2017-01-13 08:07:24 UTC
Permalink
Post by Hardik Gohil
I would like to know the accuracy of time synchronization ?
Then you need to measure it, using a PPS signal for example.
Post by Hardik Gohil
And the difference between path delay and master offset ?
The path delay is the measured Ethernet propagation time between slave
and master.
Post by Hardik Gohil
the value of master offset is the accuracy value ?
No, the master offset is estimated instantaneous time difference
between the slave and the master.

HTH,
Richard
Hardik Gohil
2017-01-13 08:20:09 UTC
Permalink
Post by Hardik Gohil
I would like to know the accuracy of time synchronization ?
you mean I need to generate PPS signal from CPU ? after that what should
be next step ?

basically my aim is to synchronize CPU system time to GPS using PTP.
Then you need to measure it, using a PPS signal for example.
Post by Hardik Gohil
And the difference between path delay and master offset ?
The path delay is the measured Ethernet propagation time between slave
and master.
Post by Hardik Gohil
the value of master offset is the accuracy value ?
No, the master offset is estimated instantaneous time difference
between the slave and the master.
HTH,
Richard
I have a message when I configure GPS to Peer-to-Peer

ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp
ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp
ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp

I cannot know what is happening
Hardik Gohil
2017-01-16 08:19:15 UTC
Permalink
Hello,

Can anybody help me to understand this message

I have a message when I configure GPS to work PTP in Peer-to-Peer mode

ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp
ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp
ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp



Regards,
Hardik A Gohil
Post by Hardik Gohil
Post by Hardik Gohil
I would like to know the accuracy of time synchronization ?
you mean I need to generate PPS signal from CPU ? after that what should
be next step ?
basically my aim is to synchronize CPU system time to GPS using PTP.
Then you need to measure it, using a PPS signal for example.
Post by Hardik Gohil
And the difference between path delay and master offset ?
The path delay is the measured Ethernet propagation time between slave
and master.
Post by Hardik Gohil
the value of master offset is the accuracy value ?
No, the master offset is estimated instantaneous time difference
between the slave and the master.
HTH,
Richard
I have a message when I configure GPS to Peer-to-Peer
ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp
ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp
ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp
I cannot know what is happening
Richard Cochran
2017-01-16 12:09:59 UTC
Permalink
Post by Hardik Gohil
I have a message when I configure GPS to work PTP in Peer-to-Peer mode
It is not enough to configure the master alone, you must also
configure the slave in P2P mode.
Post by Hardik Gohil
ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp
ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp
ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp
This means that the application received a PDelay_Req message, but the
driver did not provide a HW time stamp.

This error most likely indicates a driver or HW problem.

The fact that you have three such messages all occurring within one
millisecond of each other is suspicious. You should think about that
and find out why this is happening.

HTH,
Richard
Hardik Gohil
2017-01-17 08:25:39 UTC
Permalink
Post by Richard Cochran
Post by Hardik Gohil
I have a message when I configure GPS to work PTP in Peer-to-Peer mode
It is not enough to configure the master alone, you must also
configure the slave in P2P mode.
Yes I have done.
ptp4l -i eth0 -m -A (The -A enables automatic selection of the delay
measurement mechanism.)
Post by Richard Cochran
Post by Hardik Gohil
ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp
ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp
ptp4l[18815.624]: port 1: received PDELAY_REQ without timestamp
This means that the application received a PDelay_Req message, but the
driver did not provide a HW time stamp.
This error most likely indicates a driver or HW problem.
The fact that you have three such messages all occurring within one
millisecond of each other is suspicious. You should think about that
and find out why this is happening.
sorry for my mistake I have copied and pasted same message three times.
following are real time message

ptp4l[2460.587]: port 1: received PDELAY_REQ without timestamp
ptp4l[2461.589]: port 1: received PDELAY_REQ without timestamp
ptp4l[2462.590]: port 1: received PDELAY_REQ without timestamp
ptp4l[2463.590]: port 1: received PDELAY_REQ without timestamp
ptp4l[2464.592]: port 1: received PDELAY_REQ without timestamp
ptp4l[2465.594]: port 1: received PDELAY_REQ without timestamp
ptp4l[2466.594]: port 1: received PDELAY_REQ without timestamp

once I exit from application
[ 2506.471859] cpts: unable to obtain a time stamp
[ 2514.487888] cpts: event pool is empty

HTH,
Post by Richard Cochran
Richard
Richard Cochran
2017-01-17 10:59:55 UTC
Permalink
Post by Hardik Gohil
sorry for my mistake I have copied and pasted same message three times.
following are real time message
ptp4l[2460.587]: port 1: received PDELAY_REQ without timestamp
ptp4l[2461.589]: port 1: received PDELAY_REQ without timestamp
ptp4l[2462.590]: port 1: received PDELAY_REQ without timestamp
ptp4l[2463.590]: port 1: received PDELAY_REQ without timestamp
ptp4l[2464.592]: port 1: received PDELAY_REQ without timestamp
ptp4l[2465.594]: port 1: received PDELAY_REQ without timestamp
ptp4l[2466.594]: port 1: received PDELAY_REQ without timestamp
once I exit from application
[ 2506.471859] cpts: unable to obtain a time stamp
[ 2514.487888] cpts: event pool is empty
The driver (or HW) is not providing time stamps on these messages.

Does your device have both MACs active? If so, check whether
active_slave in the dts is correct.

IIRC, the cpts does work with P2P. Which kernel version are you
using? Is your kernel a mainline kernel, or a vendor kernel?

Thanks,
Richard
Hardik Gohil
2017-01-19 08:51:23 UTC
Permalink
Post by Richard Cochran
Post by Hardik Gohil
sorry for my mistake I have copied and pasted same message three times.
following are real time message
ptp4l[2460.587]: port 1: received PDELAY_REQ without timestamp
ptp4l[2461.589]: port 1: received PDELAY_REQ without timestamp
ptp4l[2462.590]: port 1: received PDELAY_REQ without timestamp
ptp4l[2463.590]: port 1: received PDELAY_REQ without timestamp
ptp4l[2464.592]: port 1: received PDELAY_REQ without timestamp
ptp4l[2465.594]: port 1: received PDELAY_REQ without timestamp
ptp4l[2466.594]: port 1: received PDELAY_REQ without timestamp
once I exit from application
[ 2506.471859] cpts: unable to obtain a time stamp
[ 2514.487888] cpts: event pool is empty
The driver (or HW) is not providing time stamps on these messages.
Does your device have both MACs active? If so, check whether
active_slave in the dts is correct.
both MAC means eth0 and eth1 you mean ? yes they are active.

compatible = "ti,cpsw";
ti,hwmods = "cpgmac0";
clocks = <&cpsw_125mhz_gclk>, <&cpsw_cpts_rft_clk>;
clock-names = "fck", "cpts";
cpdma_channels = <8>;
ale_entries = <1024>;
bd_ram_size = <0x2000>;
no_bd_ram = <0>;
rx_descs = <64>;
mac_control = <0x20>;
slaves = <2>;
active_slave = <0>;
cpts_clock_mult = <0x80000000>;
cpts_clock_shift = <29>;
reg = <0x4a100000 0x800
0x4a101200 0x100>;
#address-cells = <1>;
#size-cells = <1
Post by Richard Cochran
IIRC, the cpts does work with P2P. Which kernel version are you
using? Is your kernel a mainline kernel, or a vendor kernel?
I am using kernel version 3.12.30-AM335x-PD15.2.1 build using YOCTO by
PHYTEC.
I think vendor kernel.
Post by Richard Cochran
Thanks,
Richard
Richard Cochran
2017-01-22 15:42:56 UTC
Permalink
Post by Hardik Gohil
both MAC means eth0 and eth1 you mean ? yes they are active.
active_slave = <0>;
So is there a PTP peer device connected on slave 1 (probably =eth1) as
well? That would explain the messages, as the HW+driver only support
one active PTP port.
Post by Hardik Gohil
I am using kernel version 3.12.30-AM335x-PD15.2.1 build using YOCTO by
PHYTEC.
I think vendor kernel.
If the above hint doesn't explain your issue, then your next step is
to try a mainline linux kernel.

Thanks,
Richard
Hardik Gohil
2017-01-23 01:58:22 UTC
Permalink
Post by Richard Cochran
Post by Hardik Gohil
both MAC means eth0 and eth1 you mean ? yes they are active.
active_slave = <0>;
So is there a PTP peer device connected on slave 1 (probably =eth1) as
well? That would explain the messages, as the HW+driver only support
one active PTP port.
currently I am using eth0 as peer device.
Post by Richard Cochran
Post by Hardik Gohil
I am using kernel version 3.12.30-AM335x-PD15.2.1 build using YOCTO by
PHYTEC.
I think vendor kernel.
If the above hint doesn't explain your issue, then your next step is
to try a mainline linux kernel.
Richard Cochran
2017-01-23 05:33:30 UTC
Permalink
Post by Hardik Gohil
currently I am using eth0 as peer device.
And are you using dual_emac mode?

Thanks,
Richard
Hardik Gohil
2017-01-25 07:49:48 UTC
Permalink
Post by Richard Cochran
Post by Hardik Gohil
currently I am using eth0 as peer device.
And are you using dual_emac mode?
yes using dual emac mode.

sorry for late response.
Richard Cochran
2017-01-25 08:38:45 UTC
Permalink
Post by Hardik Gohil
yes using dual emac mode.
That explains it. I don't think dual emac and cpts will work together.
At least I never tested it.
Post by Hardik Gohil
sorry for late response.
No problem.

Thanks,
Richard

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