Re: [PATCH net-next 1/2] netdevsim: add link speed support

[Hangbin Liu]

Hi Andrew,
On Mon, Aug 31, 2026 at 02:24:54PM +0200, Andrew Lunn wrote:
> > +static int nsim_get_link_ksettings(struct net_device *dev,
> > +                              struct ethtool_link_ksettings *cmd)
> > +{
> > +   struct netdevsim *ns = netdev_priv(dev);
> > +
> > +   cmd->base.speed         = ns->ethtool.speed;
> > +   cmd->base.duplex        = ns->ethtool.duplex;
> > +   cmd->base.port          = PORT_OTHER;
> > +   cmd->base.autoneg       = AUTONEG_DISABLE;
> 
> Here you hard code autoneg as disabled.
> 
> > +static int nsim_set_link_ksettings(struct net_device *dev,
> > +                              const struct ethtool_link_ksettings *cmd)
> > +{
> > +   struct netdevsim *ns = netdev_priv(dev);
> > +
> > +   if (cmd->base.speed > NSIM_LINK_SPEED_MAX)
> > +           return -EINVAL;
> > +
> > +   return ethtool_virtdev_set_link_ksettings(dev, cmd, &ns->ethtool.speed,
> > +                                             &ns->ethtool.duplex);
> 
> but here you don't appear to block enabling autoneg. I would expect a
> test and EOPNOTSUPP.

ethtool_virtdev_set_link_ksettings will check the cmds and only allow user
to set speed and duplex. If a user tries to set autoneg it will return
-EINVAL. Do you want nsim to return -EOPNOTSUPP specifically?

Thanks
Hangbin