[ovs-dev] [PATCH v2 1/1] docs: Add flow control on i40e issue

[Ilya Maximets]

On 10/6/20 1:12 PM, Stokes, Ian wrote:
>> On 2/17/20 12:37 PM, Tomasz Konieczny wrote:
>>> There is an issue with flow control configuration on i40e devices
>>> and it has a work around. We add this to documentation as known issue
>>> until a permanent solution is developed.
>>
>> Hi.
>>
>> I'm looking through old patches and it seem like this one might be still
>> useful, but it wasn't actually applied.
>>
>> Does this issue still exist or it was fixed in some DPDK stable versions?
>>
>> If not, I could apply this patch to master and backport down to 2.13.
>>
>> Best regards, Ilya Maximets.
> 
> Hi Ilya,
> 
> I had time to check this out yesterday, I was able to reproduce the issue current master back as far as OVS 2.11 so it seems to still be an issue for the active DPDKs.
> 
> I'm happy to backport the patch as far as 2.11 if that sounds OK with you?

Sure, thanks!

Best regards, Ilya Maximets.

> 
> Regards
> Ian
>>
>>>
>>> Signed-off-by: Tomasz Konieczny <tomaszx.konieczny at intel.com>
>>> ---
>>>  Documentation/intro/install/dpdk.rst | 9 +++++++++
>>>  Documentation/topics/dpdk/phy.rst    | 2 ++
>>>  2 files changed, 11 insertions(+)
>>>
>>> diff --git a/Documentation/intro/install/dpdk.rst
>> b/Documentation/intro/install/dpdk.rst
>>> index dbf88ec..be47a11 100644
>>> --- a/Documentation/intro/install/dpdk.rst
>>> +++ b/Documentation/intro/install/dpdk.rst
>>> @@ -687,6 +687,15 @@ Limitations
>>>    around is temporary and is expected to be removed once a method is
>> provided
>>>    by DPDK to query the upper bound MTU value for a given device.
>>>
>>> +- Flow Control: When using i40e devices (Intel(R) 700 Series) it is
>> recommended
>>> +  to set Link State Change detection to interrupt mode. Otherwise it has been
>>> +  observed that using the default polling mode, flow control changes may not
>> be
>>> +  applied, and flow control states will not be reflected correctly.
>>> +  The issue is under investigation, this is a temporary work around.
>>> +
>>> +  For information about setting Link State Change detection, refer to
>>> +  :ref:`lsc-detection`.
>>> +
>>>  Reporting Bugs
>>>  --------------
>>>
>>> diff --git a/Documentation/topics/dpdk/phy.rst
>> b/Documentation/topics/dpdk/phy.rst
>>> index 38e52c8..55a98e2 100644
>>> --- a/Documentation/topics/dpdk/phy.rst
>>> +++ b/Documentation/topics/dpdk/phy.rst
>>> @@ -385,6 +385,8 @@ Jumbo Frames
>>>  DPDK physical ports can be configured to use Jumbo Frames. For more
>>>  information, refer to :doc:`jumbo-frames`.
>>>
>>> +.. _lsc-detection:
>>> +
>>>  Link State Change (LSC) detection configuration
>>>  -----------------------------------------------
>>>
>>>
>