[dpdk-dev] [PATCH v2] net/mlx5: fix link state update

[Ferruh Yigit]

On 11/20/2020 1:50 PM, Thomas Monjalon wrote:
> 20/11/2020 11:51, Ferruh Yigit:
>> On 11/19/2020 6:42 PM, Thomas Monjalon wrote:
>>> 19/11/2020 18:48, Ferruh Yigit:
>>>> On 11/19/2020 2:20 PM, Raslan Darawsheh wrote:
>>>>> From: Benoît Ganne <bganne at cisco.com>
>>>>>
>>>>> mlx5 PMD refuses to update link state if link speed is defined but
>>>>> status is down or if link speed is undefined but status is up, even if
>>>>> the ioctl() succeeded.
>>>>> This prevents application to detect link up/down event, especially when
>>>>> the link speed is not correctly detected.
>>>>> As link speed is nice to have whereas link status is mandatory for
>>>>> operations, always update link state regardless of link speed. The
>>>>> application can then check link speed if needs be.
>>>>>
>>>>
>>>> Hi Raslan, Matan,
>>>>
>>>> Can you please provide the Fixes tag? Also should this fix backported?
>>>
>>> I think it should not be backported because it is a behaviour change
>>> relying on API doc change.
>>>
>>
>> As far as I understand, API change you mention is making 'ETH_SPEED_NUM_UNKNOWN'
>> speed value a valid value return value.
>>
>> Commit log doesn't give the context that it relies on an ethdev behavior change,
>> it sounds like it is fixing behavior in the driver, it is not possible to figure
>> out the relation without digging the mail list discussions.
>> It would be nice to update the commit log to give more details, I think problem
>> is clear but can good to add why the check was there at first place and why it
>> can be removed now, etc..
> 
> Yes I can help improving the explanations.
> 
>> Btw with LTS, with the faulty kernel driver, PMD still won't able to get link
>> speed which will prevent returning link status.
> 
> With this PMD change, the link status is returned even if link speed
> is not available.
> 

That is why I am asking if this patch should be backported :)

>> Or is the kernel driver fixed and no need to worry about this anymore?
> 
> Yes the kernel driver is fixed since a long time.
> 
> 
>