Re: [PATCH net-next] net/mlx5e: Report link down on administrative close

[manjunath.b.patil@oracle.com]

On 6/11/26 1:13 PM, manjunath.b.patil@oracle.com wrote:
> On 6/10/26 5:06 AM, Tariq Toukan wrote:
>>
>>
>> On 09/06/2026 2:42, Manjunath Patil wrote:
>>> mlx5e_update_carrier() reports both link-up and link-down carrier
>>> changes, but an administrative down does not reach it in practice. The
>>> close path first changes the port admin state and then clears
>>> MLX5E_STATE_OPENED and drops carrier silently in mlx5e_close_locked().
>>> Any queued carrier worker will skip update_carrier() once the device is
>>> no longer opened.
>>>
>>> This leaves "ip link set dev <dev> down" without a matching netdev
>>> "Link down" message, while reopening the device still reports "Link up".
>>>
>>> Report the link-down transition in mlx5e_close() before the common close
>>> helper clears the opened state and drops carrier. Guard the message with
>>> the current opened and carrier state to avoid duplicates when the netdev
>>> is already closed or carrier is already down.
>>>
>>> Assisted-by: Codex:gpt-5
>>> Signed-off-by: Manjunath Patil <manjunath.b.patil@oracle.com>
>>> ---
>>> Validation:
>>> - Built an OL8 mainline test kernel from this change.
>>> - Booted 7.1.0-rc6.bug123456.el8.v1.x86_64 on an mlx5-backed VM.
>>> - Confirmed `ip link set dev re0 down/up` and `re1 down/up` now emit
>>>    netdev `Link down` and `Link up` messages, alongside the existing 
>>> RDMA
>>>    port state notifications.
>>>
>>>   drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 3 +++
>>>   1 file changed, 3 insertions(+)
>>>
>>> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/ 
>>> drivers/net/ethernet/mellanox/mlx5/core/en_main.c
>>> index 8f2b3abe0092..a04a89f0eddf 100644
>>> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
>>> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
>>> @@ -3628,6 +3628,9 @@ int mlx5e_close(struct net_device *netdev)
>>>       mutex_lock(&priv->state_lock);
>>>       mlx5e_modify_admin_state(priv->mdev, MLX5_PORT_DOWN);
>>> +    if (test_bit(MLX5E_STATE_OPENED, &priv->state) &&
>>> +        netif_carrier_ok(netdev))
>>> +        netdev_info(netdev, "Link down\n");
>>>       err = mlx5e_close_locked(netdev);
>>>       mutex_unlock(&priv->state_lock);
>>>
>>> base-commit: e43ffb69e0438cddd72aaa30898b4dc446f664f8
>>
>> Thanks for your patch.
>>
>> I wouldn't print "Link down" as part of the "close" callback. I'd 
>> rather get it printed in the event handler. Currently there is a print 
>> there, but the callback is masked by the OPENED bit.
>>
>> This made me revisit this area, and it surely needs some more 
>> interesting enhancements.
>> I'll probably come up with some changes soon.
> 
> thank for you taking a look at this patch.
> I will hold on and wait for your changes.

Any update on this?

I checked a v7.2-rc6 based kernel. That still showed the old behavior - 
'fup re0' reports 're0: Link up', while a successful 'ifdown re0' 
remains silent.

-Manjunath

> 
> -Manjunath