Re: [dpdk-dev] [PATCH v4 3/6] net: advertise no support for keeping flow rules

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 11/1/2021 3:06 PM, Andrew Rybchenko wrote:
> On 10/21/21 9:35 AM, Dmitry Kozlyuk wrote:
>> When RTE_ETH_DEV_CAPA_FLOW_RULE_KEEP capability bit is zero,
>> the specified behavior is the same as it had been before
>> this bit was introduced. Explicitly reset it in all PMDs
>> supporting rte_flow API in order to attract the attention
>> of maintainers, who should eventually choose to advertise
>> the new capability or not. It is already known that
>> mlx4 and mlx5 will not support this capability.
>>
>> For RTE_ETH_DEV_CAPA_FLOW_SHARED_OBJECT_KEEP
>> similar action is not performed,
>> because no PMD except mlx5 supports indirect actions.
>> Any PMD that starts doing so will anyway have to consider
>> all relevant API, including this capability.
>>
>> Suggested-by: Ferruh Yigit <ferruh.yigit@intel.com>
>> Signed-off-by: Dmitry Kozlyuk <dkozlyuk@nvidia.com>
> 
> I'm sorry, but I still think that the patch is confusing.
> No strong opinion, but personally I'd go without it.

It is confusing alright to add a flag that has no impact.

But again my concern is some PMDs maintainers not being aware of
this new capability flag that has an impact in the user application.
See the level of comments to the patch from PMD maintainers.

This way gives a visibility to both PMD maintainers that some action
is required, and gives visibility to application developers and maintainers
to track the support. By time the  should go away.

Updating ethdev without updating all drivers is hard to manage.