Hi all,
This is a gentle reminder to review RFC patch series v5 ("ethdev: add Tx
timestamp slot APIs").
Regards,
Rajesh
On 08-09-2026 01:02 pm, Rajesh Kumar wrote:
The ethdev timesync API currently exposes Tx timestamps through a shared
hardware register. This requires applications to serialize timestamped
packets and does not allow correlation when multiple packets are in
flight.
This RFC proposes an ethdev interface for hardware with independent Tx
timestamp slots. The interface reports the supported timestamping
mechanism, provides a port-global slot lifecycle, and lets applications
poll each slot asynchronously after transmission.
The proposal includes the following components:
* Capability reporting for shared-register and per-packet timestamping.
* Slot allocation, asynchronous timestamp retrieval, and slot release.
* A dual-domain timestamp structure for adjusted PHC and raw hardware
time.
* Mbuf dynamic field and dynflag support for passing slot handles to Tx,
with a helper that stamps a slot handle onto an mbuf.
* Registration and process-local reset of the cached dynfield state.
* An ice PMD implementation using the 64 per-port PHY timestamp slots.
* A testpmd command to report the slot capabilities of a port.
* Programming guide documentation, split into a patch describing the
pre-existing clock/Rx timesync API and a patch describing the new Tx
timestamp slot feature.
The legacy rte_eth_timesync_read_tx_timestamp() API remains available on
devices using a shared timestamp register.
Changes since v4:
* Fixed review comments and AI observation.
* Consolidated the Tx timestamp slot API naming onto a single
rte_eth_timesync_tx_slot_{caps,alloc,read,release,stamp} prefix,
replacing the previous mix of tx_timestamp_slot_*, tx_ts_*, and
tx_slot_* spellings across the public API, PMD ops, and the ice
implementation.
* Dropped the per-port cached slot-info array in favor of a single
process-local dynfield offset/dynflag pair.
* Split the programming guide documentation out of the ethdev patch
into two dedicated patches: one documenting the pre-existing
clock/Rx timesync API, and one documenting the new Tx timestamp slot
feature, so review of the new functionality is not mixed with review
of already-existing behavior.
* Fixed inconsistent TX/Tx casing in comments, log messages, and
documentation to consistently use "Tx".
Comments and suggestions on the interface and the ice implementation are
welcome.
Rajesh Kumar (5):
ethdev: add Tx timestamp slot management APIs
doc: describe ethdev timesync clock and Rx timestamp API
doc: describe ethdev Tx timestamp slot API
net/ice: support per-packet Tx timestamp slots
app/testpmd: add Tx timestamp capabilities command
app/test-pmd/cmdline.c | 79 ++++++++
doc/guides/nics/features.rst | 15 +-
doc/guides/prog_guide/ethdev/index.rst | 1 +
doc/guides/prog_guide/ethdev/timesync.rst | 219 +++++++++++++++++++++
doc/guides/rel_notes/release_26_11.rst | 7 +
drivers/net/intel/ice/ice_ethdev.c | 211 ++++++++++++++++++++-
drivers/net/intel/ice/ice_ethdev.h | 2 +
drivers/net/intel/ice/ice_rxtx.c | 9 +-
lib/ethdev/ethdev_driver.h | 28 +++
lib/ethdev/rte_ethdev.c | 151 ++++++++++++++-
lib/ethdev/rte_ethdev.h | 220 ++++++++++++++++++++++
11 files changed, 933 insertions(+), 9 deletions(-)
create mode 100644 doc/guides/prog_guide/ethdev/timesync.rst
