ieee1394: eth1394: handle tlabel exhaustion

When eth1394 was unable to acquire a transaction label, it just dropped
outgoing packets without attempt to resend them later.

The transmit queue is now halted if no tlabel is available to
->hard_start_xmit().  A workqueue job is then scheduled to catch the
moment when ieee1394 recycled the next lot of tlabels.

Fixes http://bugzilla.kernel.org/show_bug.cgi?id=8402

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/ieee1394/eth1394.h

@@ -66,6 +66,10 @@ struct eth1394_priv {
 	int bc_dgl;			/* Outgoing broadcast datagram label */
 	struct list_head ip_node_list;	/* List of IP capable nodes	 */
 	struct unit_directory *ud_list[ALL_NODES]; /* Cached unit dir list */
+
+	struct work_struct wake;	/* Wake up after xmit failure	 */
+	struct net_device *wake_dev;	/* Stupid backlink for .wake	 */
+	nodeid_t wake_node;		/* Destination of failed xmit	 */
 };