[PATCH v2] dts: testpmd link check on port start

[Patrick Robb]

Thanks, yep not sure how I missed running dts-check-format!

Applied to next-dts with the dts-check-format fix squashed.

On Thu, Nov 6, 2025 at 10:05 AM Andrew Bailey <abailey at iol.unh.edu> wrote:

>  Raises:
> +        InteractiveCommandExecutionError: If the ports has been started
> but a port link will not come up.
> nit: fails check-format because the line is too long.
>
> Reviewed-by: Andrew Bailey <abailey at iol.unh.edu>
>
> On Wed, Nov 5, 2025 at 2:50 PM Patrick Robb <probb at iol.unh.edu> wrote:
>
>> When running our existing DTS testsuites on a new
>> NIC we observed packets would not transmit from
>> the traffic generator to the system under test
>> even after DPDK testpmd and the NIC under test
>> had indicated readiness. After investigation, we
>> determined that the existing readiness check in DTS
>> for testpmd start (checking that port is started)
>> is insufficient, because on some systems the link
>> will remain down for some measurable time, creating
>> a race condition between the testpmd port's link
>> coming up and the DTS execution reaching the packet
>> transmission step. This change will ensure that
>> testpmd start will block until the port is reporting
>> that its link is up. In addition, the interval in
>> between checking the link state has been reduced in
>> order to speed up the execution.
>>
>> Signed-off-by: Patrick Robb <probb at iol.unh.edu>
>> Tested-by: Patrick Robb <probb at iol.unh.edu>
>> ---
>>  dts/api/testpmd/__init__.py | 9 ++++++++-
>>  1 file changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/dts/api/testpmd/__init__.py b/dts/api/testpmd/__init__.py
>> index aadb7f4e70..49a847494a 100644
>> --- a/dts/api/testpmd/__init__.py
>> +++ b/dts/api/testpmd/__init__.py
>> @@ -93,6 +93,9 @@ def _requires_started_ports(func: TestPmdMethod) ->
>> TestPmdMethod:
>>
>>      Args:
>>          func: The :class:`TestPmd` method to decorate.
>> +
>> +    Raises:
>> +        InteractiveCommandExecutionError: If the ports has been started
>> but a port link will not come up.
>>      """
>>
>>      @functools.wraps(func)
>> @@ -100,6 +103,10 @@ def _wrapper(self: "TestPmd", *args: P.args,
>> **kwargs: P.kwargs) -> Any:
>>          if not self.ports_started:
>>              self._logger.debug("Ports need to be started to continue.")
>>              self.start_all_ports()
>> +        if get_ctx().topology.type is not LinkTopology.NO_LINK:
>> +            for port in self.ports:
>> +                if not self.wait_link_status_up(port.id):
>> +                    raise InteractiveCommandExecutionError(f"Port {
>> port.id} link failed to come up.")
>>
>>          return func(self, *args, **kwargs)
>>
>> @@ -265,7 +272,7 @@ def wait_link_status_up(self, port_id: int,
>> timeout=SETTINGS.timeout) -> bool:
>>              port_info = self.send_command(f"show port info {port_id}")
>>              if "Link status: up" in port_info:
>>                  break
>> -            time.sleep(0.5)
>> +            time.sleep(0.25)
>>          else:
>>              self._logger.error(f"The link for port {port_id} did not
>> come up in the given timeout.")
>>          return "Link status: up" in port_info
>> --
>> 2.49.0
>>
>>
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