[Linuxptp-users] Video driver messing with PTP

[Collins, Cris L.]

Can someone tell me why blacklisting a video driver, in this case nouveau, in CentOS 7.2 would cause the following:

Jan 18 17:52:20 ho3 ptp4l: [215.091] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:20 ho3 ptp4l: [215.202] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:20 ho3 ptp4l: [215.393] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:20 ho3 ptp4l: [215.555] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:20 ho3 ptp4l: [215.832] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:20 ho3 ptp4l: [216.043] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:21 ho3 ptp4l: [216.207] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:21 ho3 ptp4l: [216.374] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:21 ho3 ptp4l: [216.639] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:21 ho3 ptp4l: [216.995] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:22 ho3 ptp4l: [217.113] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:22 ho3 ptp4l: [217.250] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:22 ho3 ptp4l: [217.388] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:22 ho3 ptp4l: [217.513] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:22 ho3 ptp4l: [217.745] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:22 ho3 ptp4l: [217.923] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [218.250] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [218.370] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [218.524] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [218.626] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [218.798] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [218.907] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [219.014] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:24 ho3 ptp4l: [219.250] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:24 ho3 ptp4l: [219.412] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:24 ho3 ptp4l: [219.524] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:24 ho3 ptp4l: [219.752] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:24 ho3 ptp4l: [219.855] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:24 ho3 ptp4l: [219.981] clockcheck: clock jumped forward or running faster than expected!

"date" shows a time very close to that being output by the PTP server. With video driver loaded all is well. Any troubleshooting advice? There are problems with nouveau driver that I suspect are crashing the system, so I would like to turn it off to confirm, but need PTP running.

ethtool -T ens6
Time stamping parameters for ens6:
Capabilities:
hardware-transmit (SOF_TIMESTAMPING_TX_HARDWARE)
software-transmit (SOF_TIMESTAMPING_TX_SOFTWARE)
hardware-receive (SOF_TIMESTAMPING_RX_HARDWARE)
software-receive (SOF_TIMESTAMPING_RX_SOFTWARE)
software-system-clock (SOF_TIMESTAMPING_SOFTWARE)
hardware-raw-clock (SOF_TIMESTAMPING_RAW_HARDWARE)
PTP Hardware Clock: 2
Hardware Transmit Timestamp Modes:
off (HWTSTAMP_TX_OFF)
on (HWTSTAMP_TX_ON)
Hardware Receive Filter Modes:
none (HWTSTAMP_FILTER_NONE)
all (HWTSTAMP_FILTER_ALL)

ethtool -i ens6
driver: mlx4_en
version: 3.1-1.0.4 (30 Sep 2015)
firmware-version: 2.36.5120
bus-info: 0000:83:00.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: yes

Thank you for any pointers that you may provide.

[Matthew Huff]

Is it possible that you have the Nvidia native driver loaded on the machine? If I remember, the native driver won't load if nouveau is running, so it might be running now.

----
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Director of Operations | Purchase, NY 10577
OTA Management LLC | Phone: [phone]
aim: matthewbhuff | Fax: [phone]

From: Collins, Cris L. [mailto:***@gd-ms.com]
Sent: Wednesday, January 18, 2017 6:17 PM
To: linuxptp-***@lists.sourceforge.net
Subject: [Linuxptp-users] Video driver messing with PTP

Can someone tell me why blacklisting a video driver, in this case nouveau, in CentOS 7.2 would cause the following:

Jan 18 17:52:20 ho3 ptp4l: [215.091] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:20 ho3 ptp4l: [215.202] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:20 ho3 ptp4l: [215.393] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:20 ho3 ptp4l: [215.555] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:20 ho3 ptp4l: [215.832] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:20 ho3 ptp4l: [216.043] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:21 ho3 ptp4l: [216.207] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:21 ho3 ptp4l: [216.374] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:21 ho3 ptp4l: [216.639] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:21 ho3 ptp4l: [216.995] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:22 ho3 ptp4l: [217.113] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:22 ho3 ptp4l: [217.250] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:22 ho3 ptp4l: [217.388] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:22 ho3 ptp4l: [217.513] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:22 ho3 ptp4l: [217.745] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:22 ho3 ptp4l: [217.923] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [218.250] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [218.370] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [218.524] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [218.626] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [218.798] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [218.907] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:23 ho3 ptp4l: [219.014] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:24 ho3 ptp4l: [219.250] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:24 ho3 ptp4l: [219.412] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:24 ho3 ptp4l: [219.524] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:24 ho3 ptp4l: [219.752] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:24 ho3 ptp4l: [219.855] clockcheck: clock jumped forward or running faster than expected!
Jan 18 17:52:24 ho3 ptp4l: [219.981] clockcheck: clock jumped forward or running faster than expected!

"date" shows a time very close to that being output by the PTP server. With video driver loaded all is well. Any troubleshooting advice? There are problems with nouveau driver that I suspect are crashing the system, so I would like to turn it off to confirm, but need PTP running.

ethtool -T ens6
Time stamping parameters for ens6:
Capabilities:
hardware-transmit (SOF_TIMESTAMPING_TX_HARDWARE)
software-transmit (SOF_TIMESTAMPING_TX_SOFTWARE)
hardware-receive (SOF_TIMESTAMPING_RX_HARDWARE)
software-receive (SOF_TIMESTAMPING_RX_SOFTWARE)
software-system-clock (SOF_TIMESTAMPING_SOFTWARE)
hardware-raw-clock (SOF_TIMESTAMPING_RAW_HARDWARE)
PTP Hardware Clock: 2
Hardware Transmit Timestamp Modes:
off (HWTSTAMP_TX_OFF)
on (HWTSTAMP_TX_ON)
Hardware Receive Filter Modes:
none (HWTSTAMP_FILTER_NONE)
all (HWTSTAMP_FILTER_ALL)

ethtool -i ens6
driver: mlx4_en
version: 3.1-1.0.4 (30 Sep 2015)
firmware-version: 2.36.5120
bus-info: 0000:83:00.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: yes

Thank you for any pointers that you may provide.

[Richard Cochran]

A driver that isn't loader cannot possibly affect your system.
What you really mean is that the propriety nvidea driver causes
this warning to appear, right?

Post by Collins, Cris L.
Jan 18 17:52:20 ho3 ptp4l: [215.091] clockcheck: clock jumped forward or running faster than expected!

The clock check compares packet time stamps with the local
CLOCK_MONOTONIC. Perhaps the nvidea driver spoils the check by
causing really large latencies between packet arrival and the call to
clock_gettime(CLOCK_MONOTONIC). You can instrument the code to
confirm or deny this theory.

Post by Collins, Cris L.
hardware-transmit (SOF_TIMESTAMPING_TX_HARDWARE)
software-transmit (SOF_TIMESTAMPING_TX_SOFTWARE)
hardware-receive (SOF_TIMESTAMPING_RX_HARDWARE)
software-receive (SOF_TIMESTAMPING_RX_SOFTWARE)
software-system-clock (SOF_TIMESTAMPING_SOFTWARE)
hardware-raw-clock (SOF_TIMESTAMPING_RAW_HARDWARE)
PTP Hardware Clock: 2

Since you are using HW time stamping with a PHC, the extra latency
will not affect the synchronization very much, and so you can disable
the warning by setting sanity_freq_limit to zero.

You could also try running ptp4l with a real time scheduling priority,
using the chrt utility.

Thanks,
Richard