diff mbox series

[v1,5/6] doc: update sample app with unknown speed

Message ID 20200427095737.11082-6-i.dyukov@samsung.com (mailing list archive)
State Superseded, archived
Delegated to: Ferruh Yigit
Headers
Series ethdev: allow unknown link speed |

Checks

Context Check Description
ci/checkpatch warning coding style issues
ci/Intel-compilation success Compilation OK

Commit Message

Ivan Dyukov April 27, 2020, 9:57 a.m. UTC 
  Signed-off-by: Ivan Dyukov <i.dyukov@samsung.com>
---
 doc/guides/sample_app_ug/link_status_intr.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Andrew Rybchenko May 1, 2020, 1:28 p.m. UTC | #1 
On 4/27/20 12:57 PM, Ivan Dyukov wrote:
> Signed-off-by: Ivan Dyukov <i.dyukov@samsung.com>
> ---
>   doc/guides/sample_app_ug/link_status_intr.rst | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/doc/guides/sample_app_ug/link_status_intr.rst b/doc/guides/sample_app_ug/link_status_intr.rst
> index 5283be8b7..6ebc707b7 100644
> --- a/doc/guides/sample_app_ug/link_status_intr.rst
> +++ b/doc/guides/sample_app_ug/link_status_intr.rst
> @@ -177,7 +177,8 @@ An example callback function that has been written as indicated below.
>               printf("Failed to get port %d link status: %s\n\n",
>                      port_id, rte_strerror(-ret));
>           } else if (link.link_status) {
> -            printf("Port %d Link Up - speed %u Mbps - %s\n\n", port_id, (unsigned)link.link_speed,
> +            printf("Port %d Link Up - speed %u%s - %s\n\n", port_id, (unsigned)link.link_speed,
> +                  (link.link_speed == UINT32_MAX) ? ("(UNKNOWN)") : (" Mbps"),
>                     (link.link_duplex == ETH_LINK_FULL_DUPLEX) ? ("full-duplex") : ("half-duplex"));
>           } else
>               printf("Port %d Link Down\n\n", port_id);
> 

I think that 0 looks nicer than UINT32_MAX when printed as integer
keeping in mind that it is unknown.
Ivan Dyukov May 2, 2020, 7:35 p.m. UTC | #2 
01.05.2020 16:28, Andrew Rybchenko пишет:
> On 4/27/20 12:57 PM, Ivan Dyukov wrote:
>> Signed-off-by: Ivan Dyukov <i.dyukov@samsung.com>
>> ---
>>   doc/guides/sample_app_ug/link_status_intr.rst | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/doc/guides/sample_app_ug/link_status_intr.rst 
>> b/doc/guides/sample_app_ug/link_status_intr.rst
>> index 5283be8b7..6ebc707b7 100644
>> --- a/doc/guides/sample_app_ug/link_status_intr.rst
>> +++ b/doc/guides/sample_app_ug/link_status_intr.rst
>> @@ -177,7 +177,8 @@ An example callback function that has been 
>> written as indicated below.
>>               printf("Failed to get port %d link status: %s\n\n",
>>                      port_id, rte_strerror(-ret));
>>           } else if (link.link_status) {
>> -            printf("Port %d Link Up - speed %u Mbps - %s\n\n", 
>> port_id, (unsigned)link.link_speed,
>> +            printf("Port %d Link Up - speed %u%s - %s\n\n", port_id, 
>> (unsigned)link.link_speed,
>> +                  (link.link_speed == UINT32_MAX) ? ("(UNKNOWN)") : 
>> (" Mbps"),
>>                     (link.link_duplex == ETH_LINK_FULL_DUPLEX) ? 
>> ("full-duplex") : ("half-duplex"));
>>           } else
>>               printf("Port %d Link Down\n\n", port_id);
>>
>
> I think that 0 looks nicer than UINT32_MAX when printed as integer
> keeping in mind that it is unknown.
>
zero will mislead developers about real value of the link_speed. 
therefore we should print real value of the speed or print nothing. e.g.

    if (link.link_speed == UINT32_MAX)

         printf("Port %d Link Up - speed UNKNOWN - %s\n\n", port_id,
                    (link.link_duplex == ETH_LINK_FULL_DUPLEX) ? 
("full-duplex") : ("half-duplex"));
    else

         printf("Port %d Link Up - speed %u Mbps - %s\n\n", port_id, 
link.link_speed,

                     (link.link_duplex == ETH_LINK_FULL_DUPLEX) ? 
("full-duplex") : ("half-duplex"));
Andrew Rybchenko May 3, 2020, 1:57 p.m. UTC | #3 
On 5/2/20 10:35 PM, Ivan Dyukov wrote:
> 01.05.2020 16:28, Andrew Rybchenko пишет:
>> On 4/27/20 12:57 PM, Ivan Dyukov wrote:
>>> Signed-off-by: Ivan Dyukov <i.dyukov@samsung.com>
>>> ---
>>>   doc/guides/sample_app_ug/link_status_intr.rst | 3 ++-
>>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/doc/guides/sample_app_ug/link_status_intr.rst 
>>> b/doc/guides/sample_app_ug/link_status_intr.rst
>>> index 5283be8b7..6ebc707b7 100644
>>> --- a/doc/guides/sample_app_ug/link_status_intr.rst
>>> +++ b/doc/guides/sample_app_ug/link_status_intr.rst
>>> @@ -177,7 +177,8 @@ An example callback function that has been 
>>> written as indicated below.
>>>               printf("Failed to get port %d link status: %s\n\n",
>>>                      port_id, rte_strerror(-ret));
>>>           } else if (link.link_status) {
>>> -            printf("Port %d Link Up - speed %u Mbps - %s\n\n", 
>>> port_id, (unsigned)link.link_speed,
>>> +            printf("Port %d Link Up - speed %u%s - %s\n\n", port_id, 
>>> (unsigned)link.link_speed,
>>> +                  (link.link_speed == UINT32_MAX) ? ("(UNKNOWN)") : 
>>> (" Mbps"),
>>>                     (link.link_duplex == ETH_LINK_FULL_DUPLEX) ? 
>>> ("full-duplex") : ("half-duplex"));
>>>           } else
>>>               printf("Port %d Link Down\n\n", port_id);
>>>
>> I think that 0 looks nicer than UINT32_MAX when printed as integer
>> keeping in mind that it is unknown.
>>
> zero will mislead developers about real value of the link_speed. 
> therefore we should print real value of the speed or print nothing. e.g.
>
>     if (link.link_speed == UINT32_MAX)
>
>          printf("Port %d Link Up - speed UNKNOWN - %s\n\n", port_id,
>                     (link.link_duplex == ETH_LINK_FULL_DUPLEX) ? 
> ("full-duplex") : ("half-duplex"));
>     else
>
>          printf("Port %d Link Up - speed %u Mbps - %s\n\n", port_id, 
> link.link_speed,
>
>                      (link.link_duplex == ETH_LINK_FULL_DUPLEX) ? 
> ("full-duplex") : ("half-duplex"));

I'm not sure about 0 to be misleading, but it could be.
Above definitely will look better in stdout.
The only problem is code duplication in many-many places.
May be add simple function in ethdev to do it and use it in
all examples?

Please, wait more feedback before doing it.
Varghese, Vipin May 4, 2020, 1:16 a.m. UTC | #4 
Hi,

Sharing an observation especially with Fortville (X710), if the port is not started the advertised speed is not max speed (`10000` or `40000`). Hence would cross check on `link_state` be useful before display?



> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Andrew Rybchenko
> Sent: Sunday, May 3, 2020 7:27 PM
> To: Ivan Dyukov <i.dyukov@samsung.com>; Thomas Monjalon
> <thomas@monjalon.net>; dev@dpdk.org; v.kuramshin@samsung.com;
> david.marchand@redhat.com; Yigit, Ferruh <ferruh.yigit@intel.com>
> Subject: Re: [dpdk-dev] [PATCH v1 5/6] doc: update sample app with unknown
> speed
> 
> On 5/2/20 10:35 PM, Ivan Dyukov wrote:
> > 01.05.2020 16:28, Andrew Rybchenko пишет:
> >> On 4/27/20 12:57 PM, Ivan Dyukov wrote:
> >>> Signed-off-by: Ivan Dyukov <i.dyukov@samsung.com>
> >>> ---
> >>>   doc/guides/sample_app_ug/link_status_intr.rst | 3 ++-
> >>>   1 file changed, 2 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/doc/guides/sample_app_ug/link_status_intr.rst
> >>> b/doc/guides/sample_app_ug/link_status_intr.rst
> >>> index 5283be8b7..6ebc707b7 100644
> >>> --- a/doc/guides/sample_app_ug/link_status_intr.rst
> >>> +++ b/doc/guides/sample_app_ug/link_status_intr.rst
> >>> @@ -177,7 +177,8 @@ An example callback function that has been
> >>> written as indicated below.
> >>>               printf("Failed to get port %d link status: %s\n\n",
> >>>                      port_id, rte_strerror(-ret));
> >>>           } else if (link.link_status) {
> >>> -            printf("Port %d Link Up - speed %u Mbps - %s\n\n",
> >>> port_id, (unsigned)link.link_speed,
> >>> +            printf("Port %d Link Up - speed %u%s - %s\n\n",
> >>> +port_id,
> >>> (unsigned)link.link_speed,
> >>> +                  (link.link_speed == UINT32_MAX) ? ("(UNKNOWN)") :
> >>> (" Mbps"),
> >>>                     (link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
> >>> ("full-duplex") : ("half-duplex"));
> >>>           } else
> >>>               printf("Port %d Link Down\n\n", port_id);
> >>>
> >> I think that 0 looks nicer than UINT32_MAX when printed as integer
> >> keeping in mind that it is unknown.
> >>
> > zero will mislead developers about real value of the link_speed.
> > therefore we should print real value of the speed or print nothing. e.g.
> >
> >     if (link.link_speed == UINT32_MAX)
> >
> >          printf("Port %d Link Up - speed UNKNOWN - %s\n\n", port_id,
> >                     (link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
> > ("full-duplex") : ("half-duplex"));
> >     else
> >
> >          printf("Port %d Link Up - speed %u Mbps - %s\n\n", port_id,
> > link.link_speed,
> >
> >                      (link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
> > ("full-duplex") : ("half-duplex"));
> 
> I'm not sure about 0 to be misleading, but it could be.
> Above definitely will look better in stdout.
> The only problem is code duplication in many-many places.
> May be add simple function in ethdev to do it and use it in all examples?
> 
> Please, wait more feedback before doing it.
Ivan Dyukov May 4, 2020, 3:46 p.m. UTC | #5 
03.05.2020 16:57, Andrew Rybchenko пишет:
> On 5/2/20 10:35 PM, Ivan Dyukov wrote:
>> 01.05.2020 16:28, Andrew Rybchenko пишет:
>>> On 4/27/20 12:57 PM, Ivan Dyukov wrote:
>>>> Signed-off-by: Ivan Dyukov <i.dyukov@samsung.com>
>>>> ---
>>>>    doc/guides/sample_app_ug/link_status_intr.rst | 3 ++-
>>>>    1 file changed, 2 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/doc/guides/sample_app_ug/link_status_intr.rst
>>>> b/doc/guides/sample_app_ug/link_status_intr.rst
>>>> index 5283be8b7..6ebc707b7 100644
>>>> --- a/doc/guides/sample_app_ug/link_status_intr.rst
>>>> +++ b/doc/guides/sample_app_ug/link_status_intr.rst
>>>> @@ -177,7 +177,8 @@ An example callback function that has been
>>>> written as indicated below.
>>>>                printf("Failed to get port %d link status: %s\n\n",
>>>>                       port_id, rte_strerror(-ret));
>>>>            } else if (link.link_status) {
>>>> -            printf("Port %d Link Up - speed %u Mbps - %s\n\n",
>>>> port_id, (unsigned)link.link_speed,
>>>> +            printf("Port %d Link Up - speed %u%s - %s\n\n", port_id,
>>>> (unsigned)link.link_speed,
>>>> +                  (link.link_speed == UINT32_MAX) ? ("(UNKNOWN)") :
>>>> (" Mbps"),
>>>>                      (link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
>>>> ("full-duplex") : ("half-duplex"));
>>>>            } else
>>>>                printf("Port %d Link Down\n\n", port_id);
>>>>
>>> I think that 0 looks nicer than UINT32_MAX when printed as integer
>>> keeping in mind that it is unknown.
>>>
>> zero will mislead developers about real value of the link_speed.
>> therefore we should print real value of the speed or print nothing. e.g.
>>
>>      if (link.link_speed == UINT32_MAX)
>>
>>           printf("Port %d Link Up - speed UNKNOWN - %s\n\n", port_id,
>>                      (link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
>> ("full-duplex") : ("half-duplex"));
>>      else
>>
>>           printf("Port %d Link Up - speed %u Mbps - %s\n\n", port_id,
>> link.link_speed,
>>
>>                       (link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
>> ("full-duplex") : ("half-duplex"));
> I'm not sure about 0 to be misleading, but it could be.
> Above definitely will look better in stdout.
> The only problem is code duplication in many-many places.
> May be add simple function in ethdev to do it and use it in
> all examples?
Also we can introduce new printf specifier using 
register_printf_specifier function or even rewrite %u which will print 
UNKNOWN in case of
UINT32_MAX.
>
> Please, wait more feedback before doing it.
>
>
Andrew Rybchenko May 4, 2020, 3:54 p.m. UTC | #6 
On 5/4/20 6:46 PM, Ivan Dyukov wrote:
> 03.05.2020 16:57, Andrew Rybchenko пишет:
>> On 5/2/20 10:35 PM, Ivan Dyukov wrote:
>>> 01.05.2020 16:28, Andrew Rybchenko пишет:
>>>> On 4/27/20 12:57 PM, Ivan Dyukov wrote:
>>>>> Signed-off-by: Ivan Dyukov <i.dyukov@samsung.com>
>>>>> ---
>>>>>    doc/guides/sample_app_ug/link_status_intr.rst | 3 ++-
>>>>>    1 file changed, 2 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/doc/guides/sample_app_ug/link_status_intr.rst
>>>>> b/doc/guides/sample_app_ug/link_status_intr.rst
>>>>> index 5283be8b7..6ebc707b7 100644
>>>>> --- a/doc/guides/sample_app_ug/link_status_intr.rst
>>>>> +++ b/doc/guides/sample_app_ug/link_status_intr.rst
>>>>> @@ -177,7 +177,8 @@ An example callback function that has been
>>>>> written as indicated below.
>>>>>                printf("Failed to get port %d link status: %s\n\n",
>>>>>                       port_id, rte_strerror(-ret));
>>>>>            } else if (link.link_status) {
>>>>> -            printf("Port %d Link Up - speed %u Mbps - %s\n\n",
>>>>> port_id, (unsigned)link.link_speed,
>>>>> +            printf("Port %d Link Up - speed %u%s - %s\n\n", port_id,
>>>>> (unsigned)link.link_speed,
>>>>> +                  (link.link_speed == UINT32_MAX) ? ("(UNKNOWN)") :
>>>>> (" Mbps"),
>>>>>                      (link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
>>>>> ("full-duplex") : ("half-duplex"));
>>>>>            } else
>>>>>                printf("Port %d Link Down\n\n", port_id);
>>>>>
>>>> I think that 0 looks nicer than UINT32_MAX when printed as integer
>>>> keeping in mind that it is unknown.
>>>>
>>> zero will mislead developers about real value of the link_speed.
>>> therefore we should print real value of the speed or print nothing. e.g.
>>>
>>>      if (link.link_speed == UINT32_MAX)
>>>
>>>           printf("Port %d Link Up - speed UNKNOWN - %s\n\n", port_id,
>>>                      (link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
>>> ("full-duplex") : ("half-duplex"));
>>>      else
>>>
>>>           printf("Port %d Link Up - speed %u Mbps - %s\n\n", port_id,
>>> link.link_speed,
>>>
>>>                       (link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
>>> ("full-duplex") : ("half-duplex"));
>> I'm not sure about 0 to be misleading, but it could be.
>> Above definitely will look better in stdout.
>> The only problem is code duplication in many-many places.
>> May be add simple function in ethdev to do it and use it in
>> all examples?
> Also we can introduce new printf specifier using 
> register_printf_specifier function or even rewrite %u which will print 
> UNKNOWN in case of
> UINT32_MAX.

True, but it is too libc-specific as far as I know.

>> Please, wait more feedback before doing it.
>>
>>
Ivan Dyukov May 4, 2020, 6:31 p.m. UTC | #7 
04.05.2020 18:54, Andrew Rybchenko пишет:
> On 5/4/20 6:46 PM, Ivan Dyukov wrote:
>> 03.05.2020 16:57, Andrew Rybchenko пишет:
>>> On 5/2/20 10:35 PM, Ivan Dyukov wrote:
>>>> 01.05.2020 16:28, Andrew Rybchenko пишет:
>>>>> On 4/27/20 12:57 PM, Ivan Dyukov wrote:
>>>>>> Signed-off-by: Ivan Dyukov <i.dyukov@samsung.com>
>>>>>> ---
>>>>>>     doc/guides/sample_app_ug/link_status_intr.rst | 3 ++-
>>>>>>     1 file changed, 2 insertions(+), 1 deletion(-)
>>>>>>
>>>>>> diff --git a/doc/guides/sample_app_ug/link_status_intr.rst
>>>>>> b/doc/guides/sample_app_ug/link_status_intr.rst
>>>>>> index 5283be8b7..6ebc707b7 100644
>>>>>> --- a/doc/guides/sample_app_ug/link_status_intr.rst
>>>>>> +++ b/doc/guides/sample_app_ug/link_status_intr.rst
>>>>>> @@ -177,7 +177,8 @@ An example callback function that has been
>>>>>> written as indicated below.
>>>>>>                 printf("Failed to get port %d link status: %s\n\n",
>>>>>>                        port_id, rte_strerror(-ret));
>>>>>>             } else if (link.link_status) {
>>>>>> -            printf("Port %d Link Up - speed %u Mbps - %s\n\n",
>>>>>> port_id, (unsigned)link.link_speed,
>>>>>> +            printf("Port %d Link Up - speed %u%s - %s\n\n", port_id,
>>>>>> (unsigned)link.link_speed,
>>>>>> +                  (link.link_speed == UINT32_MAX) ? ("(UNKNOWN)") :
>>>>>> (" Mbps"),
>>>>>>                       (link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
>>>>>> ("full-duplex") : ("half-duplex"));
>>>>>>             } else
>>>>>>                 printf("Port %d Link Down\n\n", port_id);
>>>>>>
>>>>> I think that 0 looks nicer than UINT32_MAX when printed as integer
>>>>> keeping in mind that it is unknown.
>>>>>
>>>> zero will mislead developers about real value of the link_speed.
>>>> therefore we should print real value of the speed or print nothing. e.g.
>>>>
>>>>       if (link.link_speed == UINT32_MAX)
>>>>
>>>>            printf("Port %d Link Up - speed UNKNOWN - %s\n\n", port_id,
>>>>                       (link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
>>>> ("full-duplex") : ("half-duplex"));
>>>>       else
>>>>
>>>>            printf("Port %d Link Up - speed %u Mbps - %s\n\n", port_id,
>>>> link.link_speed,
>>>>
>>>>                        (link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
>>>> ("full-duplex") : ("half-duplex"));
>>> I'm not sure about 0 to be misleading, but it could be.
>>> Above definitely will look better in stdout.
>>> The only problem is code duplication in many-many places.
>>> May be add simple function in ethdev to do it and use it in
>>> all examples?
>> Also we can introduce new printf specifier using
>> register_printf_specifier function or even rewrite %u which will print
>> UNKNOWN in case of
>> UINT32_MAX.
> True, but it is too libc-specific as far as I know.

Yep, it has portability issues. It's GNU C extension. https://www.gnu.org/software/libc/manual/html_node/Customizing-Printf.html

>
>>> Please, wait more feedback before doing it.
>>>
>>>
>
Ferruh Yigit May 6, 2020, 5:40 p.m. UTC | #8 
On 5/3/2020 2:57 PM, Andrew Rybchenko wrote:
> On 5/2/20 10:35 PM, Ivan Dyukov wrote:
>> 01.05.2020 16:28, Andrew Rybchenko пишет:
>>> On 4/27/20 12:57 PM, Ivan Dyukov wrote:
>>>> Signed-off-by: Ivan Dyukov <i.dyukov@samsung.com>
>>>> ---
>>>>   doc/guides/sample_app_ug/link_status_intr.rst | 3 ++-
>>>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/doc/guides/sample_app_ug/link_status_intr.rst 
>>>> b/doc/guides/sample_app_ug/link_status_intr.rst
>>>> index 5283be8b7..6ebc707b7 100644
>>>> --- a/doc/guides/sample_app_ug/link_status_intr.rst
>>>> +++ b/doc/guides/sample_app_ug/link_status_intr.rst
>>>> @@ -177,7 +177,8 @@ An example callback function that has been 
>>>> written as indicated below.
>>>>               printf("Failed to get port %d link status: %s\n\n",
>>>>                      port_id, rte_strerror(-ret));
>>>>           } else if (link.link_status) {
>>>> -            printf("Port %d Link Up - speed %u Mbps - %s\n\n", 
>>>> port_id, (unsigned)link.link_speed,
>>>> +            printf("Port %d Link Up - speed %u%s - %s\n\n", port_id, 
>>>> (unsigned)link.link_speed,
>>>> +                  (link.link_speed == UINT32_MAX) ? ("(UNKNOWN)") : 
>>>> (" Mbps"),
>>>>                     (link.link_duplex == ETH_LINK_FULL_DUPLEX) ? 
>>>> ("full-duplex") : ("half-duplex"));
>>>>           } else
>>>>               printf("Port %d Link Down\n\n", port_id);
>>>>
>>> I think that 0 looks nicer than UINT32_MAX when printed as integer
>>> keeping in mind that it is unknown.
>>>
>> zero will mislead developers about real value of the link_speed. 
>> therefore we should print real value of the speed or print nothing. e.g.
>>
>>     if (link.link_speed == UINT32_MAX)
>>
>>          printf("Port %d Link Up - speed UNKNOWN - %s\n\n", port_id,
>>                     (link.link_duplex == ETH_LINK_FULL_DUPLEX) ? 
>> ("full-duplex") : ("half-duplex"));
>>     else
>>
>>          printf("Port %d Link Up - speed %u Mbps - %s\n\n", port_id, 
>> link.link_speed,
>>
>>                      (link.link_duplex == ETH_LINK_FULL_DUPLEX) ? 
>> ("full-duplex") : ("half-duplex"));
> 
> I'm not sure about 0 to be misleading, but it could be.
> Above definitely will look better in stdout.

+1

> The only problem is code duplication in many-many places.

+1

What about print signed value, so it will be "-1 UNKNOWN", not too bad as log
but concern is if it is confusing again?

> May be add simple function in ethdev to do it and use it in
> all examples?
> 
> Please, wait more feedback before doing it.
>
diff mbox series

Patch

diff --git a/doc/guides/sample_app_ug/link_status_intr.rst b/doc/guides/sample_app_ug/link_status_intr.rst
index 5283be8b7..6ebc707b7 100644
--- a/doc/guides/sample_app_ug/link_status_intr.rst
+++ b/doc/guides/sample_app_ug/link_status_intr.rst
@@ -177,7 +177,8 @@  An example callback function that has been written as indicated below.
             printf("Failed to get port %d link status: %s\n\n",
                    port_id, rte_strerror(-ret));
         } else if (link.link_status) {
-            printf("Port %d Link Up - speed %u Mbps - %s\n\n", port_id, (unsigned)link.link_speed,
+            printf("Port %d Link Up - speed %u%s - %s\n\n", port_id, (unsigned)link.link_speed,
+                  (link.link_speed == UINT32_MAX) ? ("(UNKNOWN)") : (" Mbps"),
                   (link.link_duplex == ETH_LINK_FULL_DUPLEX) ? ("full-duplex") : ("half-duplex"));
         } else
             printf("Port %d Link Down\n\n", port_id);