Hi,
Sorry for digging up an old patch, but... ;-)
dev_disable_lro() is a leftover from ancient times. If you read commit
27660515a,
there is a hint where it should go. Please, read on if you'd like to
fix this properly.
2015-11-03 3:55 GMT+01:00 Jarod Wilson <ja...@redhat.com>:
> There are some netdev features, which when disabled on an upper device,
> such as a bonding master or a bridge, must be disabled and cannot be
> re-enabled on underlying devices.
[...]
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -6288,6 +6288,44 @@ static void rollback_registered(struct net_device *dev)
> list_del(&single);
> }
>
> +static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
> + struct net_device *upper, netdev_features_t features)
> +{
> + netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
> + netdev_features_t feature;
> +
> + for_each_netdev_feature(&upper_disables, feature) {
> + if (!(upper->wanted_features & feature)
> + && (features & feature)) {
> + netdev_dbg(lower, "Dropping feature %pNF, upper dev
> %s has it off.\n",
> + &feature, upper->name);
> + features &= ~feature;
> + }
> + }
You could do this once:
disable_features = ~upper->features & features & NETIF_F_UPPER_DISABLES;
if (features & disable_features)
netdev_dbg(...)
features &= ~disable_features;
> +
> + return features;
> +}
[...]
> @@ -6370,6 +6410,10 @@ int __netdev_update_features(struct net_device *dev)
> /* driver might be less strict about feature dependencies */
> features = netdev_fix_features(dev, features);
>
> + /* some features can't be enabled if they're off an an upper device */
> + netdev_for_each_upper_dev_rcu(dev, upper, iter)
> + features = netdev_sync_upper_features(dev, upper, features);
> +
> if (dev->features == features)
> return 0;
>
This should go into netdev_fix_features(), as it is a one single place,
where are feature dependencies are verified.
[...]
> @@ -6386,6 +6430,12 @@ int __netdev_update_features(struct net_device *dev)
> return -1;
> }
>
> + /* some features must be disabled on lower devices when disabled
> + * on an upper device (think: bonding master or bridge)
> + */
> + netdev_for_each_lower_dev(dev, lower, iter)
> + netdev_sync_lower_features(dev, lower, features);
> +
[...]
This should be equal in resulting flags to:
netdev_for_each_lower_dev(dev, lower...)
netdev_update_features(lower);
because netdev_fix_features(lower) will see already changed dev->features.
Best Regards,
Michał Mirosław
