linuxptp-users — Open discussion on using the linuxptp software.

Re: [Linuxptp-users] Linux PTP on Raspberry Pi CM4 problems/workarounds

[Richard C. <ric...@gm...>]

On Wed, Nov 30, 2022 at 07:14:01AM -0800, Richard Cochran wrote:
> On Wed, Nov 30, 2022 at 02:27:19PM +0700, James Clark wrote:
> 
> > I suppose problems 4 and 5 should be reported as kernel problems, but I'm
> > not sure of the best place to do it. Should it be the raspberrypi/linux
> > issue tracker or the kernel bugzilla?

On second thought, problem 4 is perhaps a driver bug as well.

Thanks,
Richard

Re: [Linuxptp-users] Linux PTP on Raspberry Pi CM4 problems/workarounds

[Richard C. <ric...@gm...>]

On Wed, Nov 30, 2022 at 02:27:19PM +0700, James Clark wrote:

> I suppose problems 4 and 5 should be reported as kernel problems, but I'm
> not sure of the best place to do it. Should it be the raspberrypi/linux
> issue tracker or the kernel bugzilla?

The root cause of problem 4, like problems 1, 2, and 3, is the
hardware.  The issues appear to be fundamental design issues, and
little or nothing can be done in software to work around them.

Problem 5 sure sounds like a driver bug.  I would contact the author
of the driver.  If the driver is mainline, the best way is to email
the author with the netdev list on CC.

Thanks,
Richard

[Linuxptp-users] Linux PTP on Raspberry Pi CM4 problems/workarounds

[James C. <jj...@jc...>]

I have been testing Linux PTP on the Raspberry Pi CM4 for a couple of
months. Here's a summary of the problems and workarounds I've found.

Problem 1. PTP support in the kernel isn't available in the latest
Raspberry Pi kernel packages. The problem is that the PHYs on the Raspberry
Pi 4 and the CM4 have the same id, but only the latter has PTP support. The
initial addition of PTP support for the CM4 thus broke software
timestamping on the 4, and so was disabled. But they found another way to
distinguish these two PHYs (see
https://github.com/raspberrypi/linux/issues/5104#issuecomment-1304593383),
and so the support has been reenabled and should be available in the next
version of the kernel package. In the meantime, the original working kernel
packages are still available and can be used.

Problem 2. ts2phc logs many "poll returns zero, no events" errors. The
problem here is that while the driver is getting the time from the PHC, it
has to temporarily disable handling of extts events. See
https://github.com/raspberrypi/linux/issues/5231. The best workaround I've
found is to use phc2sys -E ntpshm with chrony, and then use the phc2sys  -R
and -N options to minimize how often this error occurs. These provide more
flexibility than dpoll in chrony with the PHC refclock; it helps to make
the interval being successive reads of the PHC not be an integral number of
seconds. (I was surprised how much work the driver has to do to get the
time from the PHC. I was wondering if this is because the hardware supports
SyncE.)

Problem 3. ts2phc sometimes gives the error "nmea: unable to find utc time
in leap second table". I believe this is caused by the bug that was fixed
by this commit:

https://sourceforge.net/p/linuxptp/code/ci/63fc1ef4fd5e5fc45dd4de3bf27920bb109a4357/

I built new packages for Raspberry Pi OS incorporating this and a few other
fixes.

Problem 4. ts2phc doesn't work when the network cable is unplugged. The
problem here is that the driver does not behave well when there is no
carrier: it sometimes ends up delivering 4 pps timestamps in a second. The
best workaround I have found is to start and stop the ts2phc service using
the link status. Raspberry Pi OS uses dhcpcd to manage the network. So this
can be done by using a dhcpcd hook for the CARRIER and NOCARRIER reasons.

Problem 5. When starting ts2phc on boot using systemd, it gets the error
"interface eth0 does not have a PHC". Similarly, ptp4l can get the error
"interface 'eth0' does not support requested timestamping". When I run
ethtool -T at this point in the boot process, it shows eth0 as not having a
PHC; running it a second time shows eth0 as having the PHC. So there's a
short period when a PHC is not attached to the network interface. Is this
normal? I had a look at the kernel source, and I could not see why this is
happening. Starting ts2phc from a dhcpcd hook avoids this for the server
case. For the client case, I added a oneshot service, before ptp4l and
timemaster, restarting on failure, which just calls phc_ctl.

Problem 6. (Not CM4 specific.) A Windows 11 PTP client ends up with the
time 37 seconds off. The problem here is that Windows won't use the UTC
offset supplied by the GM unless currentUtcOffsetValid is 1 in the
grandmaster settings (even though ptpTimescale is 1). I fixed this by
having systemd run pmc with an appropriate set GRANDMASTER_SETTINGS_NP
command after starting ptp4l.

I suppose problems 4 and 5 should be reported as kernel problems, but I'm
not sure of the best place to do it. Should it be the raspberrypi/linux
issue tracker or the kernel bugzilla?

I've written a guide here:

https://github.com/jclark/rpi-cm4-ptp-guide

The config files I am using are all here:

https://github.com/jclark/rpi-cm4-ptp-guide/tree/main/files

I'm relatively new to PTP, so there may well be better ways to do things.
Suggestions for improvements would be gratefully received.

James

Re: [Linuxptp-users] ptp4l in Rasberry Pi or Auduino?

[James C. <jj...@jc...>]

I have been working on a guide to using PTP on the CM4:

https://github.com/jclark/rpi-cm4-ptp-guide

Fortunately, it is not necessary to recompile the kernel.  You just need to
make sure you use the 20220830 version of the kernel. You can do this by
adding an apt pin. If you have already upgraded to a bad kernel, then you
can download and install a good version from the raspberry pi archive.
Details here:

https://github.com/jclark/rpi-cm4-ptp-guide/blob/main/os.md

This has now been fixed in the raspberrypi stable kernel:

https://github.com/raspberrypi/linux/issues/5104#issuecomment-1304593383

so it should be in the next update.

James

On Wed, Nov 30, 2022 at 3:16 AM Maciek Machnikowski <ma...@ma...>
wrote:

>
>
> On 28 Nov 2022, at 23:30, Nemo Crypto <nem...@gm...> wrote:
>
> Hi All,
> I found that Rasberry Pi CM4 has support for PTP timestamping. It has Gigabit
> Ethernet PHY with IEEE 1588 support.
> If anyone is using the same and running ptp4l on it, please respond. We
> can collaborate.
> Thanks :)
>
>
> Linuxptp runs on RPi CM4 with HW timestamping support and 1PPS in/out. See
> details in this thread:
> https://github.com/raspberrypi/linux/issues/4151#issuecomment-1214951075
>
> Bear in mind that this support was disabled in mainstream kernel and needs
> kernel recompilation to enable it.
>
> Regards
> Maciek
>
> On Monday, 28 November, 2022 at 12:00:03 pm GMT-5, Nemo Crypto <
> nem...@gm...> wrote:
>
>
> Hi Experts,
>
> I have experience developing/implementing the entire PTP stack (IEEE1588)
> in a proprietary environment. So I am familiar with PTP, but I am new to
> linuxPTP and would like to test/debug it on my own and looking for inputs
> to proceed the right way.
>
> Anyone here have tried using/running linuxptp in Rasberry Pi or Auduino?
> Or any other leads or better way to proceed is highly appreciated.
>
> _______________________________________________
> Linuxptp-users mailing list
> Lin...@li...
> https://lists.sourceforge.net/lists/listinfo/linuxptp-users
>
>
> _______________________________________________
> Linuxptp-users mailing list
> Lin...@li...
> https://lists.sourceforge.net/lists/listinfo/linuxptp-users
>

Re: [Linuxptp-users] ptp4l in Rasberry Pi or Auduino?

[Rich S. <sch...@gm...>]

See Jeff Geerling's experiment with RPi CM4s and PTP...pretty
straightforward...
https://www.youtube.com/watch?v=RvnG-ywF6_s

https://www.jeffgeerling.com/blog/2022/ptp-and-ieee-1588-hardware-timestamping-on-raspberry-pi-cm4

Rich Schmidt
US Naval Observatory


On Tue, Nov 29, 2022 at 3:17 PM Maciek Machnikowski <ma...@ma...>
wrote:

>
>
> On 28 Nov 2022, at 23:30, Nemo Crypto <nem...@gm...> wrote:
>
> Hi All,
> I found that Rasberry Pi CM4 has support for PTP timestamping. It has Gigabit
> Ethernet PHY with IEEE 1588 support.
> If anyone is using the same and running ptp4l on it, please respond. We
> can collaborate.
> Thanks :)
>
>
> Linuxptp runs on RPi CM4 with HW timestamping support and 1PPS in/out. See
> details in this thread:
> https://github.com/raspberrypi/linux/issues/4151#issuecomment-1214951075
>
> Bear in mind that this support was disabled in mainstream kernel and needs
> kernel recompilation to enable it.
>
> Regards
> Maciek
>
> On Monday, 28 November, 2022 at 12:00:03 pm GMT-5, Nemo Crypto <
> nem...@gm...> wrote:
>
>
> Hi Experts,
>
> I have experience developing/implementing the entire PTP stack (IEEE1588)
> in a proprietary environment. So I am familiar with PTP, but I am new to
> linuxPTP and would like to test/debug it on my own and looking for inputs
> to proceed the right way.
>
> Anyone here have tried using/running linuxptp in Rasberry Pi or Auduino?
> Or any other leads or better way to proceed is highly appreciated.
>
> _______________________________________________
> Linuxptp-users mailing list
> Lin...@li...
> https://lists.sourceforge.net/lists/listinfo/linuxptp-users
>
>
> _______________________________________________
> Linuxptp-users mailing list
> Lin...@li...
> https://lists.sourceforge.net/lists/listinfo/linuxptp-users
>


-- 

*"We learn from history that we learn nothing from history." *

*George Bernard Shaw *

“The ideal subject of totalitarian rule is not the convinced Nazi or the
convinced communist, but people for whom the distinction between fact and
fiction . . . and the distinction between true and false . . . no longer
exist.” —Hanna Arendt, “The Origins of Totalitarianism” (1951)

Re: [Linuxptp-users] ptp4l in Rasberry Pi or Auduino?

[Maciek M. <ma...@ma...>]

> On 28 Nov 2022, at 23:30, Nemo Crypto <nem...@gm...> wrote:
> 
> Hi All,
> I found that Rasberry Pi CM4 has support for PTP timestamping. It has Gigabit Ethernet PHY with IEEE 1588 support.
> If anyone is using the same and running ptp4l on it, please respond. We can collaborate. 
> Thanks :)
> 

Linuxptp runs on RPi CM4 with HW timestamping support and 1PPS in/out. See details in this thread: https://github.com/raspberrypi/linux/issues/4151#issuecomment-1214951075

Bear in mind that this support was disabled in mainstream kernel and needs kernel recompilation to enable it.

Regards
Maciek

> On Monday, 28 November, 2022 at 12:00:03 pm GMT-5, Nemo Crypto <nem...@gm...> wrote:
> 
> 
> Hi Experts,
> 
> I have experience developing/implementing the entire PTP stack (IEEE1588) in a proprietary environment. So I am familiar with PTP, but I am new to linuxPTP and would like to test/debug it on my own and looking for inputs to proceed the right way.
> 
> Anyone here have tried using/running linuxptp in Rasberry Pi or Auduino? Or any other leads or better way to proceed is highly appreciated.
> 
> _______________________________________________
> Linuxptp-users mailing list
> Lin...@li...
> https://lists.sourceforge.net/lists/listinfo/linuxptp-users

Re: [Linuxptp-users] ptp4l in Rasberry Pi or Auduino?

[Nemo C. <nem...@gm...>]

 Thank you for the information Chris! I will look into the BeagleBone Black.


    On Tuesday, 29 November, 2022 at 09:02:15 am GMT-5, Chris Caudle <ch...@ch...> wrote:  
 
 On Tue, November 29, 2022 6:14 am,
lin...@li... wrote:
> Anyone here have tried using/running linuxptp in Rasberry Pi or Auduino?
> Or any other leads or better way to proceed is highly appreciated.

I have not run ptp4l on Rasberry Pi, but it runs fine on BeagleBone Black.
Arduino is a very memory constrained 8-bit microcontroller.  Arduino
cannot run Linux so Linux PTP is not applicable to Arduino.

-- 
Chris Caudle



_______________________________________________
Linuxptp-users mailing list
Lin...@li...
https://lists.sourceforge.net/lists/listinfo/linuxptp-users
  

Re: [Linuxptp-users] ptp4l in Rasberry Pi or Auduino?

[Chris C. <ch...@ch...>]

On Tue, November 29, 2022 6:14 am,
lin...@li... wrote:
> Anyone here have tried using/running linuxptp in Rasberry Pi or Auduino?
> Or any other leads or better way to proceed is highly appreciated.

I have not run ptp4l on Rasberry Pi, but it runs fine on BeagleBone Black.
Arduino is a very memory constrained 8-bit microcontroller.  Arduino
cannot run Linux so Linux PTP is not applicable to Arduino.

-- 
Chris Caudle

Re: [Linuxptp-users] ptp4l in Rasberry Pi or Auduino?

[Nemo C. <nem...@gm...>]

 Hi All,
I found that Rasberry Pi CM4 has support for PTP timestamping. It has Gigabit Ethernet PHY with IEEE 1588 support.If anyone is using the same and running ptp4l on it, please respond. We can collaborate. 
Thanks :)

    On Monday, 28 November, 2022 at 12:00:03 pm GMT-5, Nemo Crypto <nem...@gm...> wrote:  
 
 Hi Experts,

I have experience developing/implementing the entire PTP stack (IEEE1588) in a proprietary environment. So I am familiar with PTP, but I am new to linuxPTP and would like to test/debug it on my own and looking for inputs to proceed the right way.

Anyone here have tried using/running linuxptp in Rasberry Pi or Auduino? Or any other leads or better way to proceed is highly appreciated.
  

[Linuxptp-users] ptp4l in Rasberry Pi or Auduino?

[Nemo C. <nem...@gm...>]

Hi Experts,

I have experience developing/implementing the entire PTP stack (IEEE1588) in a proprietary environment. So I am familiar with PTP, but I am new to linuxPTP and would like to test/debug it on my own and looking for inputs to proceed the right way.

Anyone here have tried using/running linuxptp in Rasberry Pi or Auduino? Or any other leads or better way to proceed is highly appreciated.
Thanks,Vignesh

Re: [Linuxptp-users] Unable run ptp4l using Virtual Clock

[Miroslav L. <mli...@re...>]

On Fri, Nov 25, 2022 at 02:43:34PM +0530, Amar B S wrote:
> Hi Miroslav,
> 
> Do you see any problem in the trace?

The kernel doesn't seem to be responding with any vclocks to
the ETHTOOL_MSG_PHC_VCLOCKS_GET request for srio2.

Is directory /sys/class/ptp/ptp2/ptp8 present on the system? That
should confirm that ptp8 is a vclock of ptp2.

-- 
Miroslav Lichvar

Re: [Linuxptp-users] Unable run ptp4l using Virtual Clock

[Amar B S <ama...@gm...>]

Hi Miroslav,

Do you see any problem in the trace?

Thanks
Amar

On Thu, Nov 24, 2022 at 9:59 AM Amar B S <ama...@gm...> wrote:

> Hi,
>
> I have attached the strace log.
>
> Thanks,
> Amar B S
>
> On Wed, Nov 23, 2022 at 8:00 PM Miroslav Lichvar <mli...@re...>
> wrote:
>
>> On Wed, Nov 23, 2022 at 07:53:32PM +0530, Amar B S wrote:
>> > This part of the code checks if VPHC is present using NetLink messages,
>> it
>> > seems like we are not getting the expected response, hence failing to
>> > detect the VPHC.
>>
>> Can you please run ptp4l in strace and post the output?
>>
>> --
>> Miroslav Lichvar
>>
>>

Re: [Linuxptp-users] can linuxptp run on a single system?

[Richard C. <ric...@gm...>]

On Wed, Nov 23, 2022 at 03:12:36PM +0100, Miroslav Lichvar wrote:
> This is not an issue with the protocol. As I understand it, the kernel
> will normally not send or accept a unicast packet to itself over a
> real network interface. It has the loopback interface for that.
> 
> One way to get around that is to use multiple network namespaces.

You can run 2x ptp4l, one on each port.

If you use layer2 transport (-2 command line option) then it just
works.

If you want UDP transport, then you must configure the kernel
networking stack to accept messages from itself:

	# In order to run PTP tests with two or more local interfaces, the
	# kernel must be told to accept packets from a local address.
	
	all="eth6 eth4 eth3"
	
	for x in $all; do
		echo 1 > /proc/sys/net/ipv4/conf/$x/accept_local
	done

HTH,
Richard

Re: [Linuxptp-users] Unable run ptp4l using Virtual Clock

[Amar B S <ama...@gm...>]

Hi,

I have attached the strace log.

Thanks,
Amar B S

On Wed, Nov 23, 2022 at 8:00 PM Miroslav Lichvar <mli...@re...>
wrote:

> On Wed, Nov 23, 2022 at 07:53:32PM +0530, Amar B S wrote:
> > This part of the code checks if VPHC is present using NetLink messages,
> it
> > seems like we are not getting the expected response, hence failing to
> > detect the VPHC.
>
> Can you please run ptp4l in strace and post the output?
>
> --
> Miroslav Lichvar
>
>

Re: [Linuxptp-users] can linuxptp run on a single system?

[Hamilton A. <ale...@gm...>]

no, i am not using hybrid_e2e option.
just two port, port 0 as master and port 1 as slave (ordinary clock mode),
and they are connected with cable.
run ptp4l on port 0 and run another ptp4l on port 1,  but port 0 didn't
send delay response message.

Thanks
Alex

Miroslav Lichvar <mli...@re...> 于2022年11月23日周三 22:12写道：

> On Wed, Nov 23, 2022 at 08:41:36PM +0800, Hamilton Alex wrote:
> > Hi, Miroslav:
> > Thank you for your reply!
> > but i didn't understand, on a single system, port 0 as master and port 1
> as
> > slave, and there is cable connect port 0 and port 1 for pkt
> communication.
> > why ptp protocol doesn't work this way?
>
> Are you using the hybrid_e2e option?
>
> This is not an issue with the protocol. As I understand it, the kernel
> will normally not send or accept a unicast packet to itself over a
> real network interface. It has the loopback interface for that.
>
> One way to get around that is to use multiple network namespaces.
>
> --
> Miroslav Lichvar
>
>

Re: [Linuxptp-users] Unable run ptp4l using Virtual Clock

[Miroslav L. <mli...@re...>]

On Wed, Nov 23, 2022 at 07:53:32PM +0530, Amar B S wrote:
> This part of the code checks if VPHC is present using NetLink messages, it
> seems like we are not getting the expected response, hence failing to
> detect the VPHC.

Can you please run ptp4l in strace and post the output?

-- 
Miroslav Lichvar

Re: [Linuxptp-users] Unable run ptp4l using Virtual Clock

[Amar B S <ama...@gm...>]

*    } else if (p->phc_index >= 0 && *
*           p->phc_index != interface_phc_index(interface)) {*
       * if (rtnl_iface_has_vclock(interface_name(interface),*
*                      p->phc_index)) {*
*            pr_info("%s: /dev/ptp%d is virtual clock",*
*                p->log_name, p->phc_index);*
*            interface_set_vclock(interface, p->phc_index);*
*        } else if (p->jbod) {*
*            pr_warning("%s: just a bunch of devices", p->log_name);*
*            p->phc_index = interface_phc_index(interface);*
*        } else if (phc_device) {*
*            pr_warning("%s: taking %s from the command line, "*
*                   "not the attached ptp%d", p->log_name,*
*                   phc_device, interface_phc_index(interface));*
*            p->phc_index = phc_index;*
*            p->phc_from_cmdline = 1; *
*        } else {*
*            pr_err("%s: PHC device mismatch", p->log_name);*
*            pr_err("%s: /dev/ptp%d requested, ptp%d attached",*
*                   p->log_name, phc_index,*
*                   interface_phc_index(interface));*
*            goto err_transport;*
*        }    *
*    } *

This part of the code checks if VPHC is present using NetLink messages, it
seems like we are not getting the expected response, hence failing to
detect the VPHC.


*On Wed, Nov 23, 2022 at 5:22 PM Amar B S <ama...@gm...
<ama...@gm...>> wrote:*

>
>
>
>
> *Hi Miroslav,I checked your patch and tried it, but in my setup, it's
> failing well before the part of the code you have changed.The function
> "rtnl_iface_has_vclock" determines whether the given clock is VPHC which is
> failing and hence it exits during the Initialization phase itself. *
>
>
>
>
>
>
>
>
>
>
>
>
>
> *[root@supermicrodu1 ~]# ./ptp4l -f /etc/sysconfig/config_ptp.conf -m 2 -H
> -l 6 -s -i sriov2 option slaveOnly is deprecated, please use clientOnly
> insteadptp4l[175.953]: selected /dev/ptp8 as PTP clockptp4l[175.953]: port
> 1 (sriov2): PHC device mismatchptp4l[175.953]: port 1 (sriov2): /dev/ptp8
> requested, ptp2 attachedptp4l[175.953]: failed to open port sriov2failed to
> create a clockThanks,Amar B S*
>
>
> *On Wed, Nov 23, 2022 at 1:25 PM Miroslav Lichvar <mli...@re...
> <mli...@re...>> wrote:*
>
>>
>>
>>
>>
>>
>>
>> *On Wed, Nov 23, 2022 at 01:04:42PM +0530, Amar B S wrote: > Hi Miroslav,
>> > > May I know on which kernel version, this was working fine? It turned
>> out to be a linuxptp issue. See my patch on -devel.*
>
>
>
>
>>
>>
>> * -- Miroslav Lichvar*
>>
>

Re: [Linuxptp-users] can linuxptp run on a single system?

[Miroslav L. <mli...@re...>]

On Wed, Nov 23, 2022 at 08:41:36PM +0800, Hamilton Alex wrote:
> Hi, Miroslav:
> Thank you for your reply!
> but i didn't understand, on a single system, port 0 as master and port 1 as
> slave, and there is cable connect port 0 and port 1 for pkt communication.
> why ptp protocol doesn't work this way?

Are you using the hybrid_e2e option?

This is not an issue with the protocol. As I understand it, the kernel
will normally not send or accept a unicast packet to itself over a
real network interface. It has the loopback interface for that.

One way to get around that is to use multiple network namespaces.

-- 
Miroslav Lichvar

Re: [Linuxptp-users] can linuxptp run on a single system?

[Hamilton A. <ale...@gm...>]

Hi, Miroslav:
Thank you for your reply!
but i didn't understand, on a single system, port 0 as master and port 1 as
slave, and there is cable connect port 0 and port 1 for pkt communication.
why ptp protocol doesn't work this way?

Thanks
Alex

Miroslav Lichvar <mli...@re...> 于2022年11月23日周三 16:00写道：

> On Wed, Nov 23, 2022 at 03:35:57PM +0800, Hamilton Alex wrote:
> > so I wonder whether linuxptp can run on a single system(one CPU)?
>
> You can have multiple ptp4l instances talking to each other on a
> single system, but you need to disable the loopback shortcut between
> them. The easiest way to do that is to put them in separate network
> namespaces. See ip-netns(8).
>
> --
> Miroslav Lichvar
>
>

Re: [Linuxptp-users] Unable run ptp4l using Virtual Clock

[Amar B S <ama...@gm...>]

Hi Miroslav,

I checked your patch and tried it, but in my setup, it's failing well
before the part of the code you have changed.
The function "*rtnl_iface_has_vclock*" determines whether the given clock
is VPHC which is failing and hence it exits during the Initialization phase
itself.

[root@supermicrodu1 ~]# ./ptp4l -f /etc/sysconfig/config_ptp.conf -m 2 -H
-l 6 -s -i sriov2
option slaveOnly is deprecated, please use clientOnly instead
ptp4l[175.953]: selected /dev/ptp8 as PTP clock
ptp4l[175.953]: port 1 (sriov2):* PHC device mismatch*
ptp4l[175.953]: port 1 (sriov2): /dev/ptp8 requested, ptp2 attached
ptp4l[175.953]: failed to open port sriov2
failed to create a clock

Thanks,
Amar B S



On Wed, Nov 23, 2022 at 1:25 PM Miroslav Lichvar <mli...@re...>
wrote:

> On Wed, Nov 23, 2022 at 01:04:42PM +0530, Amar B S wrote:
> > Hi Miroslav,
> >
> > May I know on which kernel version, this was working fine?
>
> It turned out to be a linuxptp issue. See my patch on -devel.
>



> --
> Miroslav Lichvar
>
>

Re: [Linuxptp-users] can linuxptp run on a single system?

[Miroslav L. <mli...@re...>]

On Wed, Nov 23, 2022 at 03:35:57PM +0800, Hamilton Alex wrote:
> so I wonder whether linuxptp can run on a single system(one CPU)?

You can have multiple ptp4l instances talking to each other on a
single system, but you need to disable the loopback shortcut between
them. The easiest way to do that is to put them in separate network
namespaces. See ip-netns(8).

-- 
Miroslav Lichvar

Re: [Linuxptp-users] Unable run ptp4l using Virtual Clock

[Miroslav L. <mli...@re...>]

On Wed, Nov 23, 2022 at 01:04:42PM +0530, Amar B S wrote:
> Hi Miroslav,
> 
> May I know on which kernel version, this was working fine?

It turned out to be a linuxptp issue. See my patch on -devel.

-- 
Miroslav Lichvar

[Linuxptp-users] can linuxptp run on a single system?

[Hamilton A. <ale...@gm...>]

Hi, Team:
I have a network switch card, there are two ports(port 0 and port 1)
connected with cable. I run linuxptp with BC mode, set port 0 as master and
port 1 as slave (freerun mode).

I can see that port 1 received the SYNC message from port 0 and port 0
received the DelayRequest message from port 1, however, port 0 is not
sending delay response message.

so I wonder whether linuxptp can run on a single system(one CPU)?

Thanks
Alex

Re: [Linuxptp-users] Unable run ptp4l using Virtual Clock

[Amar B S <ama...@gm...>]

Hi Miroslav,

May I know on which kernel version, this was working fine?

Thanks,
Amar

On Mon, Nov 21, 2022 at 3:27 PM Miroslav Lichvar <mli...@re...>
wrote:

> On Mon, Nov 21, 2022 at 03:06:44PM +0530, Amar B S wrote:
> > Hi Miroslav,
> >
> > The code was built on a dev system and I copied binaries into to test
> > system. Is it required to build on the test system where kernel support
> is
> > present ?
>
> Actually, it shouldn't matter where it is built as linuxptp includes a
> copy of the required declarations from the headers.
>
> I did a test with a recent kernel and linuxptp, and there is indeed
> something broken wrt vclocks. I'll look into that.
>
> --
> Miroslav Lichvar
>
>

Re: [Linuxptp-users] Unable run ptp4l using Virtual Clock

[Miroslav L. <mli...@re...>]

On Mon, Nov 21, 2022 at 03:06:44PM +0530, Amar B S wrote:
> Hi Miroslav,
> 
> The code was built on a dev system and I copied binaries into to test
> system. Is it required to build on the test system where kernel support is
> present ?

Actually, it shouldn't matter where it is built as linuxptp includes a
copy of the required declarations from the headers.

I did a test with a recent kernel and linuxptp, and there is indeed
something broken wrt vclocks. I'll look into that.

-- 
Miroslav Lichvar