Re: [PATCH net-next 00/10] net/hsr: Use list_head+rcu, better frame dispatch, etc.

From: Arvid Brodin <redacted>
Date: Fri, 4 Jul 2014 23:33:44 +0200

This patch series is meant to improve the HSR code in several ways:

* Better code readability.
* In general, make the code structure more like the net/bridge code (HSR 
  operates similarly to a bridge, but uses the HSR-specific frame headers to 
  break up rings, instead of the STP protocol).
* Better handling of HSR ports' net_device features.
* Use list_head and the _rcu list traversing routines instead of array of slave 
  devices.
* Make it easy to support HSR Interlink devices (for future Redbox/Quadbox 
  support).
* Somewhat better throughput on non-HAVE_EFFICIENT_UNALIGNED_ACCESS archs, due 
  to lesser copying of skb data.

The code has been tested in a ring together with other HSR nodes running 
unchanged code, on both avr32 and x86_64. There should only be one minor change 
in behaviour from a user perspective:

* Anyone using the Netlink HSR_C_GET_NODE_LIST message to dump the internal 
  node database will notice that the database now also contains the self node.

All patches pass 'checkpatch.pl --ignore CAMELCASE --max-line-length=83 
--strict' with only CHECKs, each of which have been deliberately left in place.

The final code passes sparse checks with no output.

Series applied, thanks.

Just one question:

@@ -575,6 +579,13 @@ int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 		}
 	}
 
+	for (i = 0; i < HSR_MAX_SLAVE; i++) {
+		res = netdev_rx_handler_register(slave[i], hsr_handle_frame,
+						 hsr);
+		if (res)
+			goto fail;
+	}
+
 	/* Make sure we recognize frames from ourselves in hsr_rcv() */
 	res = hsr_create_self_node(&hsr->self_node_db, hsr_dev->dev_addr,
 				   hsr->slave[1]->dev_addr);

If one of the slaves fails to register it's RX handler here, what unregisters
the slaves which already succeeded?

Thanks.