Re: [dpdk-dev] [PATCH V2] doc: add known PHY link up issue for i40e

[Jeff Guo <jia.guo@intel.com>]

On 11/9/2018 1:48 AM, Zhang, Qi Z wrote:
>
>> -----Original Message-----
>> From: Guo, Jia
>> Sent: Thursday, November 8, 2018 12:18 AM
>> To: Xing, Beilei <beilei.xing@intel.com>; Kovacevic, Marko
>> <marko.kovacevic@intel.com>; Mcnamara, John
>> <john.mcnamara@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>
>> Cc: dev@dpdk.org; Guo, Jia <jia.guo@intel.com>; Zhang, Helin
>> <helin.zhang@intel.com>; Wu, Jingjing <jingjing.wu@intel.com>
>> Subject: [PATCH V2] doc: add known PHY link up issue for i40e
>>
>> If bind i40e NICs with PMD and run application, after application quits, some
>> kernel driver may not be able to set PHY to link up again by ``ifconfig`` after
>> NICs be rebound to kernel driver.
>>
>> Signed-off-by: Jeff Guo <jia.guo@intel.com>
>> ---
>> v2->v1:
>> refine some typo and word.
>> ---
>>   doc/guides/rel_notes/known_issues.rst | 27
>> +++++++++++++++++++++++++++
>>   1 file changed, 27 insertions(+)
>>
>> diff --git a/doc/guides/rel_notes/known_issues.rst
>> b/doc/guides/rel_notes/known_issues.rst
>> index 95e4ce6..f4e3519 100644
>> --- a/doc/guides/rel_notes/known_issues.rst
>> +++ b/doc/guides/rel_notes/known_issues.rst
>> @@ -759,3 +759,30 @@ Netvsc driver and application restart
>>
>>   **Driver/Module**:
>>      ``uio_hv_generic`` module.
>> +
>> +
>> +PHY link up failed when rebind i40e NICs to kernel driver
>> +---------------------------------------------------------
>> +
>> +**Description**:
>> +   If bind i40e NICs with PMD and run application, after application quits,
>> some
>> +   kernel driver may not be able to set PHY to link up again by ``ifconfig``
>> +   after NICs be rebound to kernel driver.
> Should we switch the content of "description" and "implication"?


I think **Description** is aim to explain the meaning of the title and 
give the detail of the phenomenon to acknowledge it.

And **Implication** is what is the true thing behind the phenomenon and 
show which version will be expected to fix. I believe

other part in document is the same and it will no have a big gap here. 
If you find the problem, please give your solid reason here.

Anyway, i think it should be fine and want you could accept my explanation.


>> +
>> +**Implication**:
>> +   Before application quits, it will invokes the function ``i40e_dev_stop``,
>> +   which will set PHY to link down. This is the situation that some kernel
>> +   driver may not be able to handle link status correctly after it retakes
>> +   control of the device. It is a known PHY link configure synchronous issue
>> in
>> +   i40e kernel driver. The fix has been addressed in 2.7.4 rc version. So if
>> +   the i40e kernel driver is < 2.7.4 and before the fix be backported into
>> the
>> +   previous versions, it will encounter this issue.
>> +
>> +**Resolution/Workaround**:
>> +   If it does not help by remove and reinsert i40e kernel driver, please
>> reboot system.
>> +
>> +**Affected Environment/Platform**:
>> +   All.
>> +
>> +**Driver/Module**:
>> +   Poll Mode Driver (PMD).
>> --
>> 2.7.4