3 files changed, 8 insertions, 6 deletions

diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index 66789c3cc561..842739df23e2 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -226,7 +226,7 @@ static void fw_fill_request(struct fw_packet *packet, int tcode, int tlabel,
         packet->speed = speed;
         packet->generation = generation;
         packet->ack = 0;
-        packet->payload_bus = 0;
+        packet->payload_mapped = false;
 }
 
 /**
@@ -601,7 +601,7 @@ void fw_fill_response(struct fw_packet *response, u32 *request_header,
                 WARN(1, KERN_ERR "wrong tcode %d", tcode);
         }
 
-        response->payload_bus = 0;
+        response->payload_mapped = false;
 }
 EXPORT_SYMBOL(fw_fill_response);
 
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 418415564791..a71477541dc7 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -995,7 +995,8 @@ static int at_context_queue_packet(struct context *ctx,
                         packet->ack = RCODE_SEND_ERROR;
                         return -1;
                 }
-                packet->payload_bus = payload_bus;
+                packet->payload_bus     = payload_bus;
+                packet->payload_mapped  = true;
 
                 d[2].req_count    = cpu_to_le16(packet->payload_length);
                 d[2].data_address = cpu_to_le32(payload_bus);
@@ -1023,7 +1024,7 @@ static int at_context_queue_packet(struct context *ctx,
          */
         if (ohci->generation != packet->generation ||
             reg_read(ohci, OHCI1394_IntEventSet) & OHCI1394_busReset) {
-                if (packet->payload_length > 0)
+                if (packet->payload_mapped)
                         dma_unmap_single(ohci->card.device, payload_bus,
                                          packet->payload_length, DMA_TO_DEVICE);
                 packet->ack = RCODE_GENERATION;
@@ -1059,7 +1060,7 @@ static int handle_at_packet(struct context *context,
                 /* This packet was cancelled, just continue. */
                 return 1;
 
-        if (packet->payload_bus)
+        if (packet->payload_mapped)
                 dma_unmap_single(ohci->card.device, packet->payload_bus,
                                  packet->payload_length, DMA_TO_DEVICE);
 
@@ -1723,7 +1724,7 @@ static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
         if (packet->ack != 0)
                 goto out;
 
-        if (packet->payload_bus)
+        if (packet->payload_mapped)
                 dma_unmap_single(ohci->card.device, packet->payload_bus,
                                  packet->payload_length, DMA_TO_DEVICE);
 
diff --git a/include/linux/firewire.h b/include/linux/firewire.h
index 211a5d7d87b3..9416a461b696 100644
--- a/include/linux/firewire.h
+++ b/include/linux/firewire.h
@@ -267,6 +267,7 @@ struct fw_packet {
         void *payload;
         size_t payload_length;
         dma_addr_t payload_bus;
+        bool payload_mapped;
         u32 timestamp;
 
         /*