Dell Mellanox Family of Adapters - Manual (Page 36)

Driver Installation and Configuration Rev 1.1
Mellanox Technologies 36
a pending bounced packet is ready for reading as far as select() is concerned. If the outgoing
packet has to be fragmented, then only the first fragment is time stamped and returned to the
sending socket.
4.2.4.3 Querying Time Stamping Capabilities via ethtool
 To display Time Stamping capabilities via ethtool:
• Show Time Stamping capabilities
Example:
4.2.5 RoCE Time Stamping
RoCE Time Stamping allows you to stamp packets when they are sent to the wire / received from
the wire. The time stamp is given in a raw hardware cycles, but could be easily converted into
hardware referenced nanoseconds based time. Additionally, it enables you to query the hardware
for the hardware time, thus stamp other application's event and compare time.
4.2.5.1 Query Capabilities
Time stamping is available if and only the hardware reports it is capable of reporting it. To verify
whether RoCE Time Stamping is available, run i
bv_ex_query_device .
When time-stamping is enabled, VLAN stripping is disabled. For more info please
refer to Documentation/networking/timestamping.txt in kernel.org
ethtool -T eth
ethtool -T eth0
Time stamping parameters for p2p1:
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: none
Hardware Transmit Timestamp Modes:
off (HWTSTAMP_TX_OFF)
on (HWTSTAMP_TX_ON)
Hardware Receive Filter Modes:
none (HWTSTAMP_FILTER_NONE)
all (HWTSTAMP_FILTER_ALL)
RoCE Time Stamping is currently at beta level.
Please be aware that everything listed here is subject to change.