8.128. linuxptp

Updated linuxptp packages that fix several bugs and add various enhancements are now available for Red Hat Enterprise Linux 6.
The Linux PTP project is a software implementation of the Precision Time Protocol (PTP) according to IEEE standard 1588 for Linux. These packages provide a robust implementation of the standard and use the most relevant and modern Application Programming Interfaces (API) offered by the Linux kernel. Supporting legacy APIs and other platforms is not a goal.
The notable bug fixes and enhancements are:
* The ptp4l application can be configured to select the delay mechanism automatically. However, this configuration did not work with the P2P delay mechanism so that the delay timer was not reset and the utility did not make any peer delay measurements. This update provides a patch to address this bug and ptp4l now correctly measures the peer delay in the described scenario. (BZ#1011022)
* Previously, the measured network delay was processed with a moving average algorithm, which is sensitive to outliers. This could for example negatively affect the time of recovery from an external clock step. This update adds a support for median filtering of the measured path delay. As a result, the algorithm that is used to process the measured delay can now be configured. The median filter, which is less sensitive to outliers, is set by default. (BZ#1016356)
* When the phc2sys utility is used with a Pulse Per Second (PPS) device and the corresponding network interface or Precision Time Protocol (PTP) clock is not specified with the "-i" or "-s" option, the user has to enable the device manually by running the "echo 1 > /sys/class/ptp/ptp0/pps_enable" command before phc2sys starts. When the device is not enabled before phc2sys starts, the "failed to fetch PPS: Connection timed out" error is returned. However, this requirement was not properly documented, which could confuse the users. With this update, this information has been added to the phc2sys(8) manual page. (BZ#1019121)
In addition, this update adds the linuxptp packages to the PowerPC version of Red Hat Enterprise Linux 6. (BZ#1095400)

Note

The linuxptp packages have been upgraded to upstream version 1.4, which provides a number of bug fixes and enhancements over the previous version. (BZ#1067502)
The notable bug fixes and enhancements are:
* The ptp4l application can be configured to select the delay mechanism automatically. However, this configuration did not work with the P2P delay mechanism so that the delay timer was not reset and the utility did not make any peer delay measurements. This update provides a patch to address this bug and ptp4l now correctly measures the peer delay in the described scenario. (BZ#1011022)
* Previously, the measured network delay was processed with a moving average algorithm, which is sensitive to outliers. This could for example negatively affect the time of recovery from an external clock step. This update adds a support for median filtering of the measured path delay. As a result, the algorithm that is used to process the measured delay can now be configured. The median filter, which is less sensitive to outliers, is set by default. (BZ#1016356)
* When the phc2sys utility is used with a Pulse Per Second (PPS) device and the corresponding network interface or Precision Time Protocol (PTP) clock is not specified with the "-i" or "-s" option, the user has to enable the device manually by running the "echo 1 > /sys/class/ptp/ptp0/pps_enable" command before phc2sys starts. When the device is not enabled before phc2sys starts, the "failed to fetch PPS: Connection timed out" error is returned. However, this requirement was not properly documented, which could confuse the users. With this update, this information has been added to the phc2sys(8) manual page. (BZ#1019121)
In addition, this update adds the linuxptp packages to the PowerPC version of Red Hat Enterprise Linux 6. (BZ#1095400)

Bug Fixes

BZ#1011022
The ptp4l application can be configured to select the delay mechanism automatically. However, this configuration did not work with the P2P delay mechanism so that the delay timer was not reset and the utility did not make any peer delay measurements. This update provides a patch to address this bug and ptp4l now correctly measures the peer delay in the described scenario.
BZ#1016356
Previously, the measured network delay was processed with a moving average algorithm, which is sensitive to outliers. This could for example negatively affect the time of recovery from an external clock step. This update adds a support for median filtering of the measured path delay. As a result, the algorithm that is used to process the measured delay can now be configured. The median filter, which is less sensitive to outliers, is set by default.
BZ#1019121
When the phc2sys utility is used with a Pulse Per Second (PPS) device and the corresponding network interface or Precision Time Protocol (PTP) clock is not specified with the "-i" or "-s" option, the user has to enable the device manually by running the "echo 1 > /sys/class/ptp/ptp0/pps_enable" command before phc2sys starts. When the device is not enabled before phc2sys starts, the "failed to fetch PPS: Connection timed out" error is returned. However, this requirement was not properly documented, which could confuse the users. With this update, this information has been added to the phc2sys(8) manual page.
The linuxptp packages have been upgraded to upstream version 1.4, which provides a number of bug fixes and enhancements over the previous version. (BZ#1067502)
The notable bug fixes and enhancements are:
In addition, this update adds the linuxptp packages to the PowerPC version of Red Hat Enterprise Linux 6. (BZ#1095400)
Users of linuxptp are advised to upgrade to these updated packages, which fix these bugs and add these enhancements.