RE: [PATCH v2] bonding: force enable lacp port after link state recovery for 802.3ad

[zhangsha (A)]

> -----Original Message-----
> From: David Miller [mailto:davem@xxxxxxxxxxxxx]
> Sent: 2019年8月28日 6:05
> To: zhangsha (A) <zhangsha.zhang@xxxxxxxxxx>
> Cc: j.vosburgh@xxxxxxxxx; vfalico@xxxxxxxxx; andy@xxxxxxxxxxxxx;
> netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; yuehaibing
> <yuehaibing@xxxxxxxxxx>; hunongda <hunongda@xxxxxxxxxx>;
> Chenzhendong (alex) <alex.chen@xxxxxxxxxx>
> Subject: Re: [PATCH v2] bonding: force enable lacp port after link state
> recovery for 802.3ad
> 
> From: <zhangsha.zhang@xxxxxxxxxx>
> Date: Fri, 23 Aug 2019 11:42:09 +0800
> 
> > - If speed/duplex getting failed here, the link status
> >   will be changed to BOND_LINK_FAIL;
> 
> How does it fail at this step?  I suspect this is a driver specific problem.

Hi, David,
I'm really sorry for the delayed email and appreciated for your feedback.

I was testing in kernel 4.19 with a Huawei hinic card when the problem occurred.
I checked the dmesg and got the logs in the following order:
1) link status definitely down for interface eth6, disabling it
2) link status up again after 0 ms for interface eth6
3) the paterner's system mac becomes to "00:00:00:00:00:00".
By  reading the codes, I think that the link status of the slave should be changed
to BOND_LINK_FAIL from BOND_LINK_DOWN. 

As this problem has only occurred once only, I am not very sure about whether this is a
driver specific problem or not at the moment. But I find the commit 4d2c0cda, 
its log says " Some NIC drivers don't have correct speed/duplex settings at the
time they send NETDEV_UP notification ...",  so I prefer to believe it's not.

To my problem I think  it is not enough that link-monitoring (miimon) only set
SPEED/DUPLEX right, the lacp port should be enabled too at the same time.