On Wed, Feb 22, 2017 at 10:31 AM, Tino Mettler <tino.mett...@tikei.de> 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
