firewire: core: always enable cycle master packets

As part of the bus manager responsibilities, make sure that the cycle
master sends cycle start packets.  This is needed when the old bus
manager disabled the cycle master's cmstr bit and there are iso-capable
nodes on the new bus.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

drivers/firewire/core-card.c

@@ -369,10 +369,8 @@ static void fw_card_bm_work(struct work_struct *work)
 		goto out;
 	} else if (root_device_is_cmc) {
 		/*
-		 * FIXME: I suppose we should set the cmstr bit in the
-		 * STATE_CLEAR register of this node, as described in
-		 * 1394-1995, 8.4.2.6.  Also, send out a force root
-		 * packet for this node.
+		 * We will send out a force root packet for this
+		 * node as part of the gap count optimization.
 		 */
 		new_root_id = root_id;
 	} else {
@@ -413,10 +411,24 @@ static void fw_card_bm_work(struct work_struct *work)
 		fw_send_phy_config(card, new_root_id, generation, gap_count);
 		fw_core_initiate_bus_reset(card, 1);
 		/* Will allocate broadcast channel after the reset. */
-	} else {
+		goto out;
+	}
+
+	if (root_device_is_cmc) {
+		/*
+		 * Make sure that the cycle master sends cycle start packets.
+		 */
+		card->bm_transaction_data[0] = cpu_to_be32(CSR_STATE_BIT_CMSTR);
+		rcode = fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
+				root_id, generation, SCODE_100,
+				CSR_REGISTER_BASE + CSR_STATE_SET,
+				card->bm_transaction_data, sizeof(u32));
+		if (rcode == RCODE_GENERATION)
+			goto out;
+	}
+
 	if (local_id == irm_id)
 		allocate_broadcast_channel(card, generation);
-	}
 
  out:
 	fw_node_put(root_node);