Bug#855834: linuxptp: default startup argument "-i eth0" should be removed

[Tino Mettler]

On Wed, Feb 22, 2017 at 13:44:43 +, Lange Norbert wrote:
> Hello,
> 
> ptp4l can find the fitting ptp device (without eth tool), this doesnt seem to 
> be a problem.

You are the second person stating this today, but I still think it is a
misunderstanding regarding the network interface (like eth0) and the
ptp device (/dev/ptpX).

> The only time where you don`t have to specify a ethernet device might
> be if you have only one (cant test this now).  I can attest that it
> will complain if you have a single one that would be PTP capable, but
> have multiple others as well.

It will always complain. Both according to the documentation and
according to my own setup (one ethernet interface -> still need to
specify the ethernet interface).

Regards,
Tino

Bug#855834: linuxptp: default startup argument "-i eth0" should be removed

[Lange Norbert]

Hello,

ptp4l can find the fitting ptp device (without eth tool), this doesnt seem to 
be a problem.

The only time where you don`t have to specify a ethernet device might be if you 
have only one (cant test this now).
I can attest that it will complain if you have a single one that would be PTP 
capable, but have multiple others as well.

Kind regards, Norbert

 >-Original Message-
 >From: Tino Mettler [mailto:tino.mett...@tikei.de]
 >Sent: Mittwoch, 22. Februar 2017 14:32
 >To: Felipe Sateler; 855...@bugs.debian.org
 >Cc: Lange Norbert
 >Subject: classified SPAM:Re: Bug#855834: linuxptp: default startup argument 
 >"-i
 >eth0" should be removed
 >
 >EXTERNAL EMAIL, please exercise caution
 >
 >
 >On Wed, Feb 22, 2017 at 09:51:25 -0300, Felipe Sateler wrote:
 >
 >[...]
 >
 >> The readme suggests ptp4l can detect appropiate devices by itself. If
 >> that is true, then there is no problem to be solved :).
 >
 >Hi,
 >
 >do you mean this?
 >
 >-
 >   If the ethtool ioctl is available, then the ptp4l program will use
 >   it in order to discover the proper PHC device.
 >-
 >
 >This means that ptp4l can find the proper PHC device (/dev/ptpX) that
 >belongs to a certain ethernet interface (like eth0).  Before that, the
 >user had to specify both the ethernet interface (-i) and the PHC device
 >(-p) to use.
 >
 >The ethernet interface still has to be specified either on the command
 >line (-i option) or in the config file.
 >
 >From the manual page:
 >
 >
 >   -i interface
 >  Specify  a PTP port, it may be used multiple times. At
 >  least one port must be specified by this option or in
 >  the configuration file.
 >
 >
 >
 >>
 >> If that is not true, I suggest the following:
 >>
 >> 1. Convert ptp4l into a template unit, ptp4l@.service
 >> 2. Change the device to be the instance:
 >> ExecStart=ExecStart=/usr/sbin/ptp4l -f /etc/linuxptp/ptp4l.conf -i %i
 >> 3. Do not enable the unit.
 >> 4. Add a udev rule that starts the (properly instanced) service when
 >> it is detected.
 >>
 >> You can see the ifupdown package for a similar approach: there is
 >> ifup@.service, a udev rule, and a helper program (ifupdown-hotplug)
 >> that determines if an instance should be started for the given device.
 >
 >Thanks. I don't fully understand 4. What exactly should be detected,
 >and how?
 >
 >> While I looked at the service files, I noticed you order them after
 >> chrony, ntpdate and other time services. Systemd defines a standard
 >> place for that, so you can replace all those alternatives with
 >> `time-sync.target`.
 >
 >Thanks for the suggestions. Currently, I just look how Fedora sets up
 >the services and do the same, so I'm always open for suggestions how to
 >improve them.
 >
 >Regards,
 >Tino


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Bug#855834: linuxptp: default startup argument "-i eth0" should be removed

[Felipe Sateler]

On Wed, Feb 22, 2017 at 10:31 AM, Tino Mettler  wrote:
> On Wed, Feb 22, 2017 at 09:51:25 -0300, Felipe Sateler wrote:
>
> [...]
>
>> The readme suggests ptp4l can detect appropiate devices by itself. If
>> that is true, then there is no problem to be solved :).
>
> Hi,
>
> do you mean this?
>
> -
>If the ethtool ioctl is available, then the ptp4l program will use
>it in order to discover the proper PHC device.
> -

Yes, that's what I was reading.

>
> This means that ptp4l can find the proper PHC device (/dev/ptpX) that
> belongs to a certain ethernet interface (like eth0).  Before that, the
> user had to specify both the ethernet interface (-i) and the PHC device
> (-p) to use.
>
> The ethernet interface still has to be specified either on the command
> line (-i option) or in the config file.
>
> From the manual page:
>
> 
>-i interface
>   Specify  a PTP port, it may be used multiple times. At
>   least one port must be specified by this option or in
>   the configuration file.
> 

OK. I don't have any clue about linuxptp, so I'm going by what I read.

>
>
>>
>> If that is not true, I suggest the following:
>>
>> 1. Convert ptp4l into a template unit, ptp4l@.service
>> 2. Change the device to be the instance:
>> ExecStart=ExecStart=/usr/sbin/ptp4l -f /etc/linuxptp/ptp4l.conf -i %i
>> 3. Do not enable the unit.
>> 4. Add a udev rule that starts the (properly instanced) service when
>> it is detected.
>>
>> You can see the ifupdown package for a similar approach: there is
>> ifup@.service, a udev rule, and a helper program (ifupdown-hotplug)
>> that determines if an instance should be started for the given device.
>
> Thanks. I don't fully understand 4. What exactly should be detected,
> and how?

A network card. A rule like the following:

SUBSYSTEM=="net", ACTION=="add|remove", RUN+="ptp-hotplug "

Will run the program /lib/udev/ptp-hotplug. In that program you should
be able to use the INTERFACE environment variable to then start the
appropriate service:

if [ -d /run/systemd/system ] ; then
  systemctl --no-block start \
   $(systemd-escape --template linuxptp@.service $INTERFACE)
  systemctl --no-block start \
   $(systemd-escape --template phc2sys@.service $INTERFACE)
fi

>
>> While I looked at the service files, I noticed you order them after
>> chrony, ntpdate and other time services. Systemd defines a standard
>> place for that, so you can replace all those alternatives with
>> `time-sync.target`.
>
> Thanks for the suggestions. Currently, I just look how Fedora sets up
> the services and do the same, so I'm always open for suggestions how to
> improve them.

Great. Hopefully the service files eventually reach upstream...

-- 

Saludos,
Felipe Sateler

Bug#855834: linuxptp: default startup argument "-i eth0" should be removed

[Tino Mettler]

On Wed, Feb 22, 2017 at 09:51:25 -0300, Felipe Sateler wrote:

[...]

> The readme suggests ptp4l can detect appropiate devices by itself. If
> that is true, then there is no problem to be solved :).

Hi,

do you mean this?

-
   If the ethtool ioctl is available, then the ptp4l program will use
   it in order to discover the proper PHC device.
-

This means that ptp4l can find the proper PHC device (/dev/ptpX) that
belongs to a certain ethernet interface (like eth0).  Before that, the
user had to specify both the ethernet interface (-i) and the PHC device
(-p) to use.

The ethernet interface still has to be specified either on the command
line (-i option) or in the config file.

>From the manual page:


   -i interface
  Specify  a PTP port, it may be used multiple times. At
  least one port must be specified by this option or in
  the configuration file.



> 
> If that is not true, I suggest the following:
> 
> 1. Convert ptp4l into a template unit, ptp4l@.service
> 2. Change the device to be the instance:
> ExecStart=ExecStart=/usr/sbin/ptp4l -f /etc/linuxptp/ptp4l.conf -i %i
> 3. Do not enable the unit.
> 4. Add a udev rule that starts the (properly instanced) service when
> it is detected.
> 
> You can see the ifupdown package for a similar approach: there is
> ifup@.service, a udev rule, and a helper program (ifupdown-hotplug)
> that determines if an instance should be started for the given device.

Thanks. I don't fully understand 4. What exactly should be detected,
and how? 

> While I looked at the service files, I noticed you order them after
> chrony, ntpdate and other time services. Systemd defines a standard
> place for that, so you can replace all those alternatives with
> `time-sync.target`.

Thanks for the suggestions. Currently, I just look how Fedora sets up
the services and do the same, so I'm always open for suggestions how to
improve them.

Regards,
Tino

Bug#855834: linuxptp: default startup argument "-i eth0" should be removed

[Felipe Sateler]

Hi

On Wed, Feb 22, 2017 at 7:36 AM, Tino Mettler  wrote:
> On Wed, Feb 22, 2017 at 10:59:08 +0100, Norbert Lange wrote:
>
> [...]
>
>> I would recommend removing the argument, and add a section for the device in 
>> the
>> configuration file. can be a placeholder like [eth0], I would not know
>> of a good default name that would fit most systems.
>
> Hi,
>
> thanks for the comments. If I got this right, there won't be a default
> name that would fit most systems as of Stretch and later.

That is correct.

>
> A userfriedly approach would be to look for a device with PTP support
> and use this, or supply a debconf request with devices that can be
> used. I'll try to incorporate this. My debconf foo is limited. though,
> so this might take a while.

The readme suggests ptp4l can detect appropiate devices by itself. If
that is true, then there is no problem to be solved :).

If that is not true, I suggest the following:

1. Convert ptp4l into a template unit, ptp4l@.service
2. Change the device to be the instance:
ExecStart=ExecStart=/usr/sbin/ptp4l -f /etc/linuxptp/ptp4l.conf -i %i
3. Do not enable the unit.
4. Add a udev rule that starts the (properly instanced) service when
it is detected.

You can see the ifupdown package for a similar approach: there is
ifup@.service, a udev rule, and a helper program (ifupdown-hotplug)
that determines if an instance should be started for the given device.



While I looked at the service files, I noticed you order them after
chrony, ntpdate and other time services. Systemd defines a standard
place for that, so you can replace all those alternatives with
`time-sync.target`.


-- 

Saludos,
Felipe Sateler

Bug#855834: linuxptp: default startup argument "-i eth0" should be removed

[Tino Mettler]

On Wed, Feb 22, 2017 at 10:59:08 +0100, Norbert Lange wrote:

[...]

> I would recommend removing the argument, and add a section for the device in 
> the
> configuration file. can be a placeholder like [eth0], I would not know
> of a good default name that would fit most systems.

Hi,

thanks for the comments. If I got this right, there won't be a default
name that would fit most systems as of Stretch and later.

A userfriedly approach would be to look for a device with PTP support
and use this, or supply a debconf request with devices that can be
used. I'll try to incorporate this. My debconf foo is limited. though,
so this might take a while.

Regards,
Tino

Bug#855834: linuxptp: default startup argument "-i eth0" should be removed

[Norbert Lange]

Package: linuxptp
Version: 1.8-1
Severity: normal

Dear Maintainer,

a default installation of debian stretch will not use eth0 as
ethernet device name anymore, also see [1].

using this as commandline argument when starting this service is troublesome,
as it can`t be undone. The documention claims you can use an empty port section,
to override the but I am not sure how this should be done, as that will just
result in an error.

I had to edit the systemd unit file to get the service starting.

I would recommend removing the argument, and add a section for the device in the
configuration file. can be a placeholder like [eth0], I would not know
of a good default name that would fit most systems.

Kind regards,
Norbert Lange


[1] 
https://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames

-- System Information:
Debian Release: 9.0
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.9.0-1-rt-amd64 (SMP w/4 CPU cores; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages linuxptp depends on:
ii  init-system-helpers  1.47
ii  libc62.24-9

linuxptp recommends no packages.

linuxptp suggests no packages.

-- no debconf information