Re: [PATCH net V2 10/11] net/mlx5e: Update and set Xon/Xoff upon port speed set

Tariq Toukan
2025-09-17T13:39:00Z

On 17/09/2025 16:00, Daniel Zahka wrote:
>
>
> On 9/17/25 6:39 AM, Tariq Toukan wrote:
>>
>>
>> On 15/09/2025 10:38, Tariq Toukan wrote:
>>>
>>>
>>> On 11/09/2025 17:36, Jakub Kicinski wrote:
>>>> On Thu, 11 Sep 2025 17:25:22 +0300 Mark Bloch wrote:
>>>>> On 11/09/2025 16:47, Jakub Kicinski wrote:
>>>>>> On Wed, 10 Sep 2025 17:00:11 -0700 Jakub Kicinski wrote:
>>>>>>> Hi, this is breaking dual host CX7 w/ 28.45.1300 (but I think most
>>>>>>> older FW versions, too). Looks like the host is not receiving any
>>>>>>> mcast (ping within a subnet doesn't work because the host receives
>>>>>>> no ndisc), and most traffic slows down to a trickle.
>>>>>>> Lost of rx_prio0_buf_discard increments.
>>>>>>>
>>>>>>> Please TAL ASAP, this change went to LTS last week.
>>>>>>
>>>>>> Any news on this? I heard that it also breaks DCB/QoS configuration
>>>>>> on 6.12.45 LTS.
>>>>>
>>>>> We are looking into this, once we have anything I'll update.
>>>>> Just to make sure, reverting this is one commit solves the
>>>>> issue you are seeing?
>>>>
>>>> It did for me, but Daniel (who is working on the PSP series)
>>>> mentioned that he had reverted all three to get net-next working:
>>>>
>>>>    net/mlx5e: Set local Xoff after FW update
>>>>    net/mlx5e: Update and set Xon/Xoff upon port speed set
>>>>    net/mlx5e: Update and set Xon/Xoff upon MTU set
>>>>
>>>
>>> Hi Jakub,
>>>
>>> Thanks for reporting.
>>> We're investigating and will update soon.
>>>
>>> Regards,
>>> Tariq
>>>
>>
>> Hi,
>>
>> We prefer reverting the single patch [1] for now. We'll submit a fixed
>> version later.
>>
>> Regarding the other two patches [2], initial testing showed no issues.
>> Can you/Daniel share more info? What issues you see, and the repro steps.
>>
>> Thanks,
>> Tariq
>>
>> [1]
>> net/mlx5e: Update and set Xon/Xoff upon port speed set
>>
>> [2]
>> net/mlx5e: Set local Xoff after FW update
>> net/mlx5e: Update and set Xon/Xoff upon MTU set
>>
>
> Hello Tariq,
>
> My notes for the situation were that I was running a vanilla net-next
> kernel on a dual host, CX7 system, with the 28.45.1300 FW at commit:
>
> deb105f49879 net: phy: marvell: Fix 88e1510 downshift counter errata
>
> and I was having the issues that Jakub described. No ping working in a
> subnet. Extremely slow bandwidth on a large transfer. My notes say that
> reverting just [1] (from your message) did not fix the problem, but then
> reverting [2] and [3] restored normal behavior.
>
> However, I did attempt to reproduce again on the same system this
> morning, and now I'm seeing that reverting just [1] is sufficient to fix
> the issues.

I see.
For now, I'll submit a revert only for [1].

Let us know of any related issue you still hit after the revert.

Thanks.