Le 07-03-21 à 11:02, Viacheslav Ovsiienko a écrit :
> There are two different timestamp formats can be provided potentially
> by mlx5 supported hardware.
>
> The free-running format provides some opaque values captured from
> internal clock counter clocked by some independent oscillator.
> The free-running frequency is not pre-defined and should be queried
> from the NIC.
How is the UTC clock kept in sync with the host? It would be interesting 
to mention a bit about that when you'll send the patch for the 
"timestamp format context field", as it's important for precise 
measurements.
>
> The real-time timestamps are presented in nanoseconds and captured from
> the dedicated UTC counter, that can be adjusted on the fly and might be
> synchronized with some external master clock.
>
> Depending on the version and configuration the hardware might support
> either FR or RT timestamps, or both in the same time on per queue basis.
> Since firmware version xx.30.0256 the timestamp format can be configured
> via fields in the queue context at the object creation time. For the
> compatibility reasons the default zero value configures timestamps with
> free-running format. The NIC ConnectX-5 and earlier ones support the
> free-running format only. Since ConnectX-6 both formats might be supported
> and configured. The default zero value (specified in the non-defined
> yet timestamp format context field) causes the queue creation
> failure (rejected by firmware) if the NIC is configured to real-time timestamp
> format. Hence, it is crucial to check whether firmware/hardware supports
> timestamp formats and configure queues accordingly, and this patchset
> also must be provided for stable DPDK releases.
>
> Compatibility affected (without this patchset) summary:
>    - ConnectX-6DX or BlueField 2

Your commit message mention CX6 but the compatibility summary CX6DX. 
Which one started to get support?

Thanks,

Tom

>    - real-time format is configured in NV settings
>    - firmware is xx.30.0256 or higher
>
> Viacheslav Ovsiienko (5):
>    common/mlx5: add timestamp format support to DevX
>    net/mlx5: add timestamp format support
>    vdpa/mlx5: add timestamp format support
>    regex/mlx5: add timestamp format support
>    compress/mlx5: add timestamp format support
>
>   drivers/common/mlx5/mlx5_devx_cmds.c    | 35 +++++++++++++++++++--
>   drivers/common/mlx5/mlx5_devx_cmds.h    |  7 +++++
>   drivers/common/mlx5/mlx5_prm.h          | 41 ++++++++++++++++++++++---
>   drivers/compress/mlx5/mlx5_compress.c   |  5 +++
>   drivers/net/mlx5/linux/mlx5_os.c        |  3 ++
>   drivers/net/mlx5/mlx5.h                 |  3 ++
>   drivers/net/mlx5/mlx5_devx.c            | 12 +++++++-
>   drivers/net/mlx5/mlx5_flow_age.c        | 10 ++++--
>   drivers/net/mlx5/mlx5_txpp.c            |  8 +++++
>   drivers/net/mlx5/windows/mlx5_os.c      |  3 ++
>   drivers/regex/mlx5/mlx5_regex.c         |  1 +
>   drivers/regex/mlx5/mlx5_regex.h         |  1 +
>   drivers/regex/mlx5/mlx5_regex_control.c |  4 +++
>   drivers/vdpa/mlx5/mlx5_vdpa.c           |  1 +
>   drivers/vdpa/mlx5/mlx5_vdpa.h           |  1 +
>   drivers/vdpa/mlx5/mlx5_vdpa_event.c     |  8 +++++
>   16 files changed, 133 insertions(+), 10 deletions(-)
>