Re: [PATCH net] selftests/net: set link down before enslave

[Ido Schimmel <idosch@idosch.org>]

On Wed, Jan 20, 2021 at 10:38:47PM +0800, Hangbin Liu wrote:
> Hi Ido,
> 
> On Wed, Jan 20, 2021 at 12:42:10PM +0200, Ido Schimmel wrote:
> > > diff --git a/tools/testing/selftests/net/rtnetlink.sh b/tools/testing/selftests/net/rtnetlink.sh
> > > index c9ce3dfa42ee..a26fddc63992 100755
> > > --- a/tools/testing/selftests/net/rtnetlink.sh
> > > +++ b/tools/testing/selftests/net/rtnetlink.sh
> > > @@ -1205,6 +1205,8 @@ kci_test_bridge_parent_id()
> > >  	dev20=`ls ${sysfsnet}20/net/`
> > >  
> > >  	ip link add name test-bond0 type bond mode 802.3ad
> > > +	ip link set dev $dev10 down
> > > +	ip link set dev $dev20 down
> > 
> > But these netdevs are created with their administrative state set to
> > 'DOWN'. Who is setting them to up?
> 
> Would you please point me where we set the state to 'DOWN'? Cause on my
> host it is init as UP:
> 
> ++ ls /sys/bus/netdevsim/devices/netdevsim10/net/
> + dev10=eth3
> ++ ls /sys/bus/netdevsim/devices/netdevsim20/net/
> + dev20=eth4
> + ip link add name test-bond0 type bond mode 802.3ad
> + ip link show eth3
> 66: eth3: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
>     link/ether 1e:52:27:5f:a5:3c brd ff:ff:ff:ff:ff:ff

I didn't have time to look into this today, but I suspect the problem is
either:

1. Some interface manager on your end that is setting these interfaces
up after they are created

2. A bug in netdevsim that does not initialize the carrier to off.
Maybe try with this patch (didn't test):

diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index aec92440eef1..1e0dc298bf20 100644
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -312,6 +312,8 @@ nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port)
 
        nsim_ipsec_init(ns);
 
+       netif_carrier_off(dev);
+
        err = register_netdevice(dev);
        if (err)
                goto err_ipsec_teardown;

> 
> # uname -r
> 5.11.0-rc3+
> 
> Thanks
> Hangbin