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

Daniel Zahka
2025-09-17T13:00:52Z

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.