RHBA-2014:1491 - Bug Fix Advisory

Topic

Updated linuxptp packages that fix several bugs and add various enhancements are
now available for Red Hat Enterprise Linux 6.

Description

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 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)

Users of linuxptp are advised to upgrade to these updated packages, which fix
these bugs and add these enhancements.

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Workstation 6 x86_64

Fixes

• BZ - 1011022 - Auto delay mechanism doesn't work with P2P
• BZ - 1067502 - rebase linuxptp to 1.4

CVEs

(none)

References

(none)