[PATCH v3 0/2] ethdev: add the check for PTP capability

[Ferruh Yigit]

On 8/17/2023 9:42 AM, Huisong Li wrote:
> From the first version of ptpclient, it seems that this example assume that
> the PMDs support the PTP feature and enable PTP by default. Please see
> commit ab129e9065a5 ("examples/ptpclient: add minimal PTP client")
> which are introduced in 2015.
> 
> And two years later, Rx HW timestamp offload was introduced to enable or
> disable PTP feature in HW via rte_eth_rxmode. Please see
> commit 42ffc45aa340 ("ethdev: add Rx HW timestamp capability"). 
> 

Hi Huisong,

As far as I know this offload is not for PTP.
PTP and TIMESTAMP are different.

PTP is a protocol for time sync.
Rx TIMESTAMP offload is to ask HW to add timestamp to mbuf.

> And then about four years later, ptpclient enable Rx timestamp offload
> because some PMDs require this offload to enable. Please see
> commit 7a04a4f67dca ("examples/ptpclient: enable Rx timestamp offload").
> 

dpaa2 seems using TIMESTAMP offload and PTP together, hence they updated
ptpclient sample to set TIMESTAMP offload.

We need to clarify dpaa2 usage.

> By all the records, this is more like a process of perfecting PTP feature.
> Not all network adaptors support PTP feature. So adding the check for PTP
> capability in ethdev layer is necessary.
> 

Nope, as PTP (IEEE1588/802.1AS) implemented as dev_ops, and ops already
checked, so no additional check is needed.

We just need to clarify TIMESTAMP offload and PTP usage and find out
what is causing confusion.
I would be great if you can help on clarification, and update
documentation or API comments, or what ever required, for this.

> ---
> v3:
>  - patch [2/3] for hns3 has been applied and so remove it.
>  - ops pointer check is closer to usage.
> 
> Huisong Li (2):
>   examples/ptpclient: add the check for PTP capability
>   ethdev: add the check for the valitity of timestamp offload
> 
>  examples/ptpclient/ptpclient.c |  5 +++
>  lib/ethdev/rte_ethdev.c        | 57 +++++++++++++++++++++++++++++++++-
>  2 files changed, 61 insertions(+), 1 deletion(-)
>