Re: [PATCH net-next v2 3/4] net: dsa: add support for offloading HSR

On Sat, Feb 6, 2021 at 5:29 PM Vladimir Oltean [off-list ref] wrote:

On Thu, Feb 04, 2021 at 03:59:25PM -0600, George McCollister wrote:

quoted

@@ -1935,6 +1936,19 @@ static int dsa_slave_changeupper(struct net_device *dev,
                      dsa_port_lag_leave(dp, info->upper_dev);
                      err = NOTIFY_OK;
              }
+     } else if (is_hsr_master(info->upper_dev)) {
+             if (info->linking) {
+                     err = dsa_port_hsr_join(dp, info->upper_dev);
+                     if (err == -EOPNOTSUPP) {
+                             NL_SET_ERR_MSG_MOD(info->info.extack,
+                                                "Offloading not supported");
+                             err = 0;
+                     }
+                     err = notifier_from_errno(err);
+             } else {
+                     dsa_port_hsr_leave(dp, info->upper_dev);
+                     err = NOTIFY_OK;
+             }
      }

[..]

quoted

+static int dsa_switch_hsr_join(struct dsa_switch *ds,
+                            struct dsa_notifier_hsr_info *info)
+{
+     if (ds->index == info->sw_index && ds->ops->port_hsr_join)
+             return ds->ops->port_hsr_join(ds, info->port, info->hsr);
+
+     return 0;
+}
+
+static int dsa_switch_hsr_leave(struct dsa_switch *ds,
+                             struct dsa_notifier_hsr_info *info)
+{
+     if (ds->index == info->sw_index && ds->ops->port_hsr_leave)
+             ds->ops->port_hsr_leave(ds, info->port, info->hsr);
+
+     return 0;
+}
+

If you return zero, the software fallback is never going to kick in.

For join and leave? How is this not a problem for the bridge and lag
functions? They work the same way don't they? I figured it would be
safe to follow what they were doing.