4c5d180ab3
If ptp4l is running as a boundary clock, and multiple master ports share a hardware clock that is different than the slave port's hardware clock, then phc2sys in autocfg mode will synchronize that clock multiple times per sync loop, once per-port. Example output when this happens: CLOCK_REALTIME phc offset -9 s2 freq -355 delay 3635 eth9 phc offset 9 s2 freq +1762 delay 7488 eth8 phc offset 41 s2 freq +1985 delay 7424 eth7 phc offset 15 s2 freq +1952 delay 7440 eth6 phc offset 20 s2 freq +1059 delay 7440 eth1 phc offset 22 s2 freq +1783 delay 7424 eth12.400 phc offset 15 s2 freq -4207943 delay 7551 eth12.300 phc offset 388 s2 freq +2336645 delay 7536 eth12.200 phc offset 451 s2 freq +2516553 delay 7438 eth12.100 phc offset 268 s2 freq +64274 delay 7405 This is easily reproducible by adding VLANs to a single network interface and configuring ptp4l to use those VLAN interfaces as PTP ports. This patch prevents this problem by introducing a new deduplicated destination clock list to phc2sys. Each time phc2sys reconfigures, the destination clock list is re-populated. In the synchronization loop, phc2sys will only use the clocks in this list. Example output of reconfiguration with this patch: reconfiguring after port state change selecting eth9 for synchronization selecting eth8 for synchronization selecting eth7 for synchronization selecting eth6 for synchronization selecting eth1 for synchronization selecting eth13.400 for synchronization skipping eth13.300: eth13.400 has the same clock and is already selected skipping eth13.200: eth13.400 has the same clock and is already selected skipping eth13.100: eth13.400 has the same clock and is already selected selecting eth12.400 for synchronization skipping eth12.300: eth12.400 has the same clock and is already selected skipping eth12.200: eth12.400 has the same clock and is already selected skipping eth12.100: eth12.400 has the same clock and is already selected skipping eth13.500: eth13.400 has the same clock and is already selected This patch was tested with autocfg mode and also when specifying source and destination manually via commandline. Signed-off-by: Cliff Spradlin <cspradlin@google.com> |
||
|---|---|---|
| configs | ||
| .gitignore | ||
| CODING_STYLE.org | ||
| COPYING | ||
| README.org | ||
| address.h | ||
| bmc.c | ||
| bmc.h | ||
| clock.c | ||
| clock.h | ||
| clockadj.c | ||
| clockadj.h | ||
| clockcheck.c | ||
| clockcheck.h | ||
| config.c | ||
| config.h | ||
| contain.h | ||
| ddt.h | ||
| dm.h | ||
| ds.h | ||
| e2e_tc.c | ||
| ether.h | ||
| fault.c | ||
| fault.h | ||
| fd.h | ||
| filter.c | ||
| filter.h | ||
| filter_private.h | ||
| foreign.h | ||
| fsm.c | ||
| fsm.h | ||
| hash.c | ||
| hash.h | ||
| hwstamp_ctl.8 | ||
| hwstamp_ctl.c | ||
| incdefs.sh | ||
| linreg.c | ||
| linreg.h | ||
| makefile | ||
| mave.c | ||
| mave.h | ||
| missing.h | ||
| mmedian.c | ||
| mmedian.h | ||
| msg.c | ||
| msg.h | ||
| notification.h | ||
| nsm.c | ||
| ntpshm.c | ||
| ntpshm.h | ||
| nullf.c | ||
| nullf.h | ||
| p2p_tc.c | ||
| pdt.h | ||
| phc.c | ||
| phc.h | ||
| phc2sys.8 | ||
| phc2sys.c | ||
| phc_ctl.8 | ||
| phc_ctl.c | ||
| pi.c | ||
| pi.h | ||
| pmc.8 | ||
| pmc.c | ||
| pmc_common.c | ||
| pmc_common.h | ||
| port.c | ||
| port.h | ||
| port_private.h | ||
| print.c | ||
| print.h | ||
| ptp4l.8 | ||
| ptp4l.c | ||
| raw.c | ||
| raw.h | ||
| rtnl.c | ||
| rtnl.h | ||
| servo.c | ||
| servo.h | ||
| servo_private.h | ||
| sk.c | ||
| sk.h | ||
| stats.c | ||
| stats.h | ||
| sysoff.c | ||
| sysoff.h | ||
| tc.c | ||
| tc.h | ||
| telecom.c | ||
| timemaster.8 | ||
| timemaster.c | ||
| tlv.c | ||
| tlv.h | ||
| tmv.h | ||
| transport.c | ||
| transport.h | ||
| transport_private.h | ||
| tsproc.c | ||
| tsproc.h | ||
| udp.c | ||
| udp.h | ||
| udp6.c | ||
| udp6.h | ||
| uds.c | ||
| uds.h | ||
| util.c | ||
| util.h | ||
| version.c | ||
| version.h | ||
| version.sh | ||
README.org
- Introduction
- License
- Features
- Getting the Code
- System Requirements
- Installation
- Getting Involved
- Thanks
Introduction
This software is an implementation of the Precision Time Protocol (PTP) according to IEEE standard 1588 for Linux. The dual design goals are to provide a robust implementation of the standard and to 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.
License
The software is copyrighted by the authors and is licensed under the GNU General Public License. See the file, COPYING, for details of the license terms.
Features
- Supports hardware and software time stamping via the Linux SO_TIMESTAMPING socket option.
- Supports the Linux PTP Hardware Clock (PHC) subsystem by using the clock_gettime family of calls, including the new clock_adjtimex system call.
- Implements Boundary Clock (BC) and Ordinary Clock (OC).
- Transport over UDP/IPv4, UDP/IPv6, and raw Ethernet (Layer 2).
- Supports IEEE 802.1AS-2011 in the role of end station.
- Modular design allowing painless addition of new transports and clock servos.
Getting the Code
You can download the latest released version at Source Forge.
http://sourceforge.net/projects/linuxptp/files/latest/download
The source code is managed using the git version control system. To get your own copy of the project sources, use the following command.
git clone git://git.code.sf.net/p/linuxptp/code linuxptp
If the git protocol is blocked by your local area network, then you can use the alternative HTTP protocol instead.
git clone http://git.code.sf.net/p/linuxptp/code linuxptp
System Requirements
In order to run this software, you need Linux kernel version 3.0 or newer, and the kernel header files must available at compile time.
In addition, you will also need to have either:
- A supported Ethernet MAC device.
- A supported PHY device paired with a MAC that allows time stamping in the PHY (indicated by PHY=Y in the table below).
Linux Kernel Support
In order to support PTP, the operating system needs to provide two services: network packet time stamping and clock control. In 2009, Patrick Ohly added a new socket option called SO_TIMESTAMPING for packet time stamping, especially for PTP. This work appeared in Linux version 2.6.30.
In July of 2011, the PTP Hardware Clock (PHC) subsystem was merged into Linux version 3.0. The PHC code provides a driver framework and the user space API for clock control.
Ethtool Support
Starting with version 3.5 of the Linux kernel, you can query the time stamping capabilities of a network interface using the ETHTOOL_GET_TS_INFO ioctl. Using ethtool version 3.4 or later, you can check your system's time stamping support as shown in the following example.
ethtool -T eth0
If the ethtool ioctl is available, then the ptp4l program will use it in order to discover the proper PHC device.
Driver Support Matrix
The following two tables list the drivers that support the PHC subsystem and the Linux kernel version when they first appeared. These drivers will create a PHC device for controlling the hardware clock.
Hardware Timestamping - PHY
| Driver | Hardware | Version |
| dp83640 | National Semiconductor PHYTER | 3.0 |
Hardware Timestamping - MAC
| Driver | Hardware | Version |
| amd-xgbe | AMD 10GbE Ethernet Soc | 3.17 |
| bfin_mac | Analog Blackfin | 3.8 |
| bnx2x | Broadcom NetXtremeII 10G | 3.18 |
| cpts | Texas Instruments am335x | 3.8 |
| e1000e | Intel 82574, 82583 | 3.9 |
| fm10k | Intel FM10000 | 3.18 |
| fec | Freescale i.mx6 | 3.8 |
| gianfar | Freescale eTSEC PowerPC | 3.0 |
| i40e | Intel XL710 Family | 3.14 |
| igb | Intel 82576, 82580 | 3.5 |
| ixgbe | Intel 82599 | 3.5 |
| mlx4 | Mellanox 40G PCI | 3.14 |
| ptp_ixp46x | Intel IXP465 | 3.0 |
| ptp_phc | Lapis EG20T PCH | 3.5 |
| sfc | Solarflare SFC9000 | 3.7 |
| stmmac | STM Synopsys IP Core | 3.10 |
| tg3 | Broadcom Tigon3 PCI | 3.8 |
| tilegx | Tilera GBE/XGBE | 3.12 |
Software Timestamping
The table below shows the Linux drivers that support software time stamping. In addition, the 'PHY' column indicates whether the Ethernet MAC driver can support a PTP Hardware Clock in an external PHY. The letter 'Y' in this column means that if you design a mother board that combines such a MAC with a PTP capable PHY, then it will work with the Linux PHC subsystem.
| Driver | Hardware | Version | PHY |
| 3c59x | 3Com EtherLink PCI | 3.14 | N |
| altera_tse | Altera Triple-Speed MAC | 3.15 | Y |
| bna | Brocade 1010/1020 10Gb | 3.14 | N |
| bnx2x | Broadcom Everest | 3.5 | N |
| davinci_emac | TI DaVinci, Sitara | 3.1 | Y |
| dnet | Dave Ethernet MAC | 3.1 | Y |
| e100 | Intel PRO/100 | 3.5 | N |
| e1000 | Intel PRO/1000 PCI/PCI-X | 3.5 | N |
| e1000e | Intel PRO/1000 PCIe | 3.5 | N |
| emaclite | Xilinx Ethernet Lite | 3.1 | Y |
| ethoc | OpenCores 10/100 MAC | 3.1 | Y |
| fec | Freescale Coldfire | 3.1 | Y |
| fec_mpc52xx | Freescale MPC5200 | 3.1 | Y |
| forcedeth | NVIDIA nForce | 3.5 | N |
| fs_enet | Freescale MPC512x | 3.1 | Y |
| genet | Broadcom GENET | 3.15 | Y |
| ixp4xx_eth | Intel IXP4xx | 3.0 | Y |
| lib8390 | Asix AX88796 | 3.1 | Y |
| lib8390 | Various 8390 based HW | 3.1 | N |
| ll_temac | Xilinx LL TEMAC | 3.1 | Y |
| macb | Atmel AT32, AT91 | 3.1 | Y |
| mv643xx_eth | Marvell Discovery, Orion | 3.1 | Y |
| pxa168_eth | Marvell pxa168 | 3.1 | Y |
| r6040 | RDC Ethernet MAC | 3.1 | Y |
| r8169 | Realtek 8169/8168/8101 | 3.4 | N |
| samsun-sxgbe | Samsung SXGBE 10G | 3.15 | Y |
| smsc911x | SMSC LAN911x, LAN921x | 3.1 | Y |
| smsc9420 | SMSC LAN9420 PCI | 3.1 | Y |
| stmmac | STM Synopsys IP Core | 3.1 | Y |
| tg3 | Broadcom Tigon3 PCI | 3.1 | Y |
| ucc_geth | Freescale QE Gigabit | 3.1 | Y |
| usbnet | USB network devices | 3.2 | Y/N |
| xgene-enet | APM X-Gene SoC | 3.17 | Y |
Installation
Linux kernel
There are many ways of getting a precompiled Linux kernel or compiling your own, so this section is only meant as an example. It is important to have the kernel headers available when compiling the Linux PTP stack.
export ARCH=x86 export CROSS_COMPILE= export KBUILD_OUTPUT=/home/richard/kernel/ptp_debian mkdir -p $KBUILD_OUTPUT cp /boot/config-2.6.38-bpo.2-686 $KBUILD_OUTPUT/.config make oldnoconfig make menuconfig time make -j4 make headers_install
Here is a table of kernel configuration options needed for PTP support. In addtion to these, you should enable the specific Ethernet MAC and PHY drivers for your hardware.
| Option | Description |
| CONFIG_PPS | Required |
| CONFIG_NETWORK_PHY_TIMESTAMPING | Timestamping in PHY devices |
| PTP_1588_CLOCK | PTP clock support |
PTP stack
- Just type 'make'
- If you compiled your own kernel (and the headers are not installed into the system path), then you should set the KBUILD_OUTPUT environment variable as in the example, above.
- In order to install the programs and man pages into /usr/local, run the 'make install' target. You can change the installation directories by setttings the variables prefix, sbindir, mandir, and man8dir on the make command line.
Getting Involved
The software development is hosted at Source Forge.
https://sourceforge.net/projects/linuxptp/
Reporting Bugs
Please report any bugs or other issues with the software to the linuxptp-users mailing list.
Development
If you would like to get involved in improving the software, please join the linuxptp-devel mailing list.
https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
Submitting Patches
- Before submitting patches, please make sure that you are starting your work on the current HEAD of the git repository.
- Please checkout the
CODING_STYLE.orgfile for guidelines on how to properly format your code. - Describe your changes. Each patch will be reviewed, and the reviewers need to understand why you did what you did.
-
Sign-Off each commit, so the changes can be properly attributed to you and you explicitely give your agreement for distribution under linuxptp's license. Signing-off is as simple as:
git commit -s
or by adding the following line (replace your real name and email) to your patch:
Signed-off-by: Random J Developer <random@developer.example.org>
-
Finally, send your patches via email to the linuxptp-devel mailing list, where they will be reviewed, and eventually be included in the official code base.
git send-email --to linuxptp-devel@lists.sourceforge.net origin/master
Thanks
Thanks to AudioScience Inc for sponsoring the 8021.AS support.
Thanks to Exablaze for donating an ExaNIC X10
Thanks to Intel Corporation for donating four NICs, the 82574, 82580, 82599, and the i210.
Thanks to Meinberg Funkuhren for donating a LANTIME M1000.
For testing I use an OTMC 100 grandmaster clock donated by OMICRON Lab.