diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index 2bb5c036e806..0c312c4bb4bd 100644
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -570,12 +570,12 @@ static int dummy_set_config_rom(struct fw_card *card,
 
 static void dummy_send_request(struct fw_card *card, struct fw_packet *packet)
 {
-	packet->callback(packet, card, -ENODEV);
+	packet->callback(packet, card, RCODE_CANCELLED);
 }
 
 static void dummy_send_response(struct fw_card *card, struct fw_packet *packet)
 {
-	packet->callback(packet, card, -ENODEV);
+	packet->callback(packet, card, RCODE_CANCELLED);
 }
 
 static int dummy_cancel_packet(struct fw_card *card, struct fw_packet *packet)
diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index 5f5a7852f7ac..e2e4dc624fb6 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -310,7 +310,10 @@ static int allocate_tlabel(struct fw_card *card)
  * After the transaction is completed successfully or unsuccessfully, the
  * @callback will be called.  Among its parameters is the response code which
  * is either one of the rcodes per IEEE 1394 or, in case of internal errors,
- * the firewire-core specific %RCODE_SEND_ERROR.
+ * the firewire-core specific %RCODE_SEND_ERROR.  The other firewire-core
+ * specific rcodes (%RCODE_CANCELLED, %RCODE_BUSY, %RCODE_GENERATION,
+ * %RCODE_NO_ACK) denote transaction timeout, busy responder, stale request
+ * generation, or missing ACK respectively.
  *
  * Note some timing corner cases:  fw_send_request() may complete much earlier
  * than when the request packet actually hits the wire.  On the other hand,
diff --git a/include/linux/firewire.h b/include/linux/firewire.h
index adc5b55e6e5f..0c38b8e97722 100644
--- a/include/linux/firewire.h
+++ b/include/linux/firewire.h
@@ -285,10 +285,10 @@ struct fw_packet {
 	u32 timestamp;
 
 	/*
-	 * This callback is called when the packet transmission has
-	 * completed; for successful transmission, the status code is
-	 * the ack received from the destination, otherwise it's a
-	 * negative errno: ENOMEM, ESTALE, ETIMEDOUT, ENODEV, EIO.
+	 * This callback is called when the packet transmission has completed.
+	 * For successful transmission, the status code is the ack received
+	 * from the destination.  Otherwise it is one of the juju-specific
+	 * rcodes:  RCODE_SEND_ERROR, _CANCELLED, _BUSY, _GENERATION, _NO_ACK.
 	 * The callback can be called from tasklet context and thus
 	 * must never block.
 	 */