Re: [PATCH 1/1] bonding: restrict up state in 802.3ad mode

[Michal Kubecek <mkubecek@suse.cz>]

On Thu, Dec 17, 2015 at 01:57:16PM -0800, Jay Vosburgh wrote:
> <zyjzyj2000@gmail.com> wrote:
> >In 802.3ad mode, the speed and duplex is needed. But in some NIC,
> >there is a time span between NIC up state and getting speed and duplex.
> >As such, sometimes a slave in 802.3ad mode is in up state without
> >speed and duplex. This will make bonding in 802.3ad mode can not
> >work well. 
> >To make bonding driver be compatible with more NICs, it is
> >necessary to restrict the up state in 802.3ad mode.
> 
> 	What device is this?  It seems a bit odd that an Ethernet device
> can be carrier up but not have the duplex and speed available.
...
> 	In general, though, bonding expects a speed or duplex change to
> be announced via a NETDEV_UPDATE or NETDEV_UP notifier, which would
> propagate to the 802.3ad logic.
> 
> 	If the device here is going carrier up prior to having speed or
> duplex available, then maybe it should call netdev_state_change() when
> the duplex and speed are available, or delay calling netif_carrier_on().

I have encountered this problem (NIC having carrier on before being able
to detect speed/duplex and driver not notifying when speed/duplex
becomes available) with netxen cards earlier. But it was eventually
fixed in the driver by commit 9d01412ae76f ("netxen: Fix link event
handling.") so this example rather supports what you said.

                                                          Michal Kubecek