[dpdk-dev] [PATCH] ethdev: unify error code if port ID is invalid

[Ferruh Yigit]

On 10/14/2020 7:16 AM, Andrew Rybchenko wrote:
> On 10/13/20 7:12 PM, Ferruh Yigit wrote:
>> On 10/13/2020 4:39 PM, Andrew Rybchenko wrote:
>>> On 10/13/20 6:32 PM, Ferruh Yigit wrote:
>>>> On 10/13/2020 3:53 PM, Andrew Rybchenko wrote:
>>>>> Use ENODEV as the error code if specified port ID is invalid.
>>>>>
>>>>> Signed-off-by: Andrew Rybchenko <arybchenko at solarflare.com>
>>>>> ---
>>>>>     lib/librte_ethdev/rte_ethdev.c | 44 ++++++++++++++++----------------
>>>>>     lib/librte_ethdev/rte_ethdev.h | 46
>>>>> +++++++++++++++++++++++-----------
>>>>>     2 files changed, 54 insertions(+), 36 deletions(-)
>>>>>
>>>>> diff --git a/lib/librte_ethdev/rte_ethdev.c
>>>>> b/lib/librte_ethdev/rte_ethdev.c
>>>>> index 5b7979a3b8..1f862f918a 100644
>>>>> --- a/lib/librte_ethdev/rte_ethdev.c
>>>>> +++ b/lib/librte_ethdev/rte_ethdev.c
>>>>> @@ -784,7 +784,7 @@ rte_eth_dev_get_name_by_port(uint16_t port_id,
>>>>> char *name)
>>>>>     {
>>>>>         char *tmp;
>>>>>     -    RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
>>>>> +    RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
>>>>
>>>> Thanks Andrew, +1 to this error unification.
>>>>
>>>> This will be API change without deprecation notice, cc'ed techboard
>>>> for it.
>>>
>>> Yes, thanks.
>>>
>>>>
>>>> If this should (almost) always return '-ENODEV', does it make sense to
>>>> make another wrapper macro for it, to prevent later other error types
>>>> used again.
>>>
>>> Unlikely, since most likely the line will be simply copied.
>>> RTE_ETH_VALID_PORTID_OR_ERR_RET will remain in any case, so
>>> it will be possible to misuse it anyway.
>>>
>>
>> Agree it won't prevent misuse completely but may help, anyway I don't
>> have a strong opinion here, if you think that is not needed, that is OK.
>>
>>>>
>>>> And there are a few instances returning '-1', are they left
>>>> intentionally?
>>>
>>> Yes. Inside ethdev it is either socket_id or fd in these cases.
>>>
>>
>> Can't those two also updated to return '-ENODEV' when 'port_id' is not
>> valid?
> 
> I think no.
> 1. rte_eth_dev_socket_id() should not return -ENODEV since it
>     can return -1 even if port ID is valid if fact (I see
>     printouts from time to time if I'm not mistaken) and
>     typically handled as unspecified NUMA node ID.
> 2. rte_eth_dev_rx_intr_ctl_q_get_fd() explicitly says that -1
>     is returned on error. The function is still experimental
>     and we can change it, but I'd say that -1 match typical
>     behavior for functions returning file descriptor.
> 
> Let's limit the changeset to switch from EINVAL to ENODEV.
> 

OK.

It looks like there is no objection on the API part, so I will proceed with it 
but will get as one of the last a few patches before -rc1 to prevent other 
existing ethdev patches to conflict.