On Sat, Nov 05, 2016 at 04:38:04PM +0100, Jan Deinhard wrote: > I am using a Debian workstation and a i.MX6UL evaluation board running on a > Linux build with Yocto. According to ethtool -T eth0 both systems support > PTP hardware timestamping.
... > ptp4l[26435.632]: master offset 4399753214 s2 freq +32767999 path delay > -277121915 > > It is not getting better after some minutes. Master offset is alway > increasing and freq is always the same value. The frequency is locked here at maximum offset, and the device is not converging. This is most likely a driver or HW problem on the imx6. > Workstation: > > $ uname > -a > > Linux polaris 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1+deb8u2 (2016-10-19) > x86_64 GNU/Linux > > $ lspci > 00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (2) > I219-V (rev 31) If this i219 is working with the igb driver, and the driver shows HW time stamping enabled, then it should work well. So this isn't the problem, most likely. > Eval board: > > $ uname -a > Linux imx6ulevk 4.1.15-2.0.0+gb63f3f5 #1 SMP PREEMPT Wed Nov 2 21:42:19 CET > 2016 armv7l armv7l armv7l GNU/Linux I have never tested the ptp driver for the imx6, and I am highly suspicious of Freescale "quality" drivers. > What can I do to find out what the problem is? I guess that either the imx6 driver is broken by design, or that it is mis-configured on your board. I would verify that the input clock to the time stamping unit is the same frequency as the driver expects, or if the driver detects the frequency, that this is correct. You will probably have to dig into the data sheet and into the driver source. Here is one simple sanity check for the clock. Run testptp -g; sleep 60; testptp -g and verify that the difference between the two outputs is about 60 seconds. > Or am I misinterpreting the output? Looks like a problem on the imx6. You can run a test between the i219 and any other linux PC (even if that PC only has SW time stamping) in order to exclude a problem with the i219. > What does the "freq" value mean? This is the adjustment in parts per billion. Normally the magnitute of this value should never exceed 100 ppm or so. HTH, Richard ------------------------------------------------------------------------------ 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 Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
