[PATCH v11 2/5] ethdev: support proactive error handling mode

[Andrew Rybchenko]

On 10/9/22 12:10, Chengwen Feng wrote:
> From: Kalesh AP <kalesh-anakkur.purayil at broadcom.com>
> 
> Some PMDs (e.g. hns3) could detect hardware or firmware errors, and try
> to recover from the errors. In this process, the PMD sets the data path
> pointers to dummy functions (which will prevent the crash), and also
> make sure the control path operations failed with retcode -EBUSY.

Could you explain why passive mode is not good. Why is
proactive better? What are the benefits? IMHO, it would
be simpler to have just one error recovery mode.	
> 
> The above error handling mode is known as
> RTE_ETH_ERROR_HANDLE_MODE_PROACTIVE (proactive error handling mode).
> 
> In some service scenarios, application needs to be aware of the event
> to determine whether to migrate services. So three events were
> introduced:
> 
> 1) RTE_ETH_EVENT_ERR_RECOVERING: used to notify the application that it
> detected an error and the recovery is being started. Upon receiving the
> event, the application should not invoke any control path APIs until
> receiving RTE_ETH_EVENT_RECOVERY_SUCCESS or
> RTE_ETH_EVENT_RECOVERY_FAILED event.
> 
> 2) RTE_ETH_EVENT_RECOVERY_SUCCESS: used to notify the application that
> it recovers successful from the error, the PMD already re-configures the
> port, and the effect is the same as that of the restart operation.
> 
> 3) RTE_ETH_EVENT_RECOVERY_FAILED: used to notify the application that it
> recovers failed from the error, the port should not usable anymore. The
> application should close the port.
> 
> Signed-off-by: Kalesh AP <kalesh-anakkur.purayil at broadcom.com>
> Signed-off-by: Somnath Kotur <somnath.kotur at broadcom.com>
> Signed-off-by: Chengwen Feng <fengchengwen at huawei.com>
> Reviewed-by: Ajit Khaparde <ajit.khaparde at broadcom.com>

The code itself LGTM. I just want to understand why we need it.
It should be proved in the description.