firewire: fw-ohci: fix IOMMU resource exhaustion

There is a DMA map/ unmap imbalance whenever a block write request
packet is sent and then dequeued with ohci_cancel_packet.  The latter
may happen frequently if the AR resp tasklet is executed before the AT
req tasklet for the same transaction.

Add the missing dma_unmap_single.  This fixes
https://bugzilla.redhat.com/show_bug.cgi?id=475156

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

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/firewire/fw-transaction.c b/drivers/firewire/fw-transaction.c
index 022ac4fabb67..2884f876397b 100644
--- a/drivers/firewire/fw-transaction.c
+++ b/drivers/firewire/fw-transaction.c
@@ -207,6 +207,7 @@ fw_fill_request(struct fw_packet *packet, int tcode, int tlabel,
         packet->speed = speed;
         packet->generation = generation;
         packet->ack = 0;
+        packet->payload_bus = 0;
 }
 
 /**
@@ -581,6 +582,8 @@ fw_fill_response(struct fw_packet *response, u32 *request_header,
                 BUG();
                 return;
         }
+
+        response->payload_bus = 0;
 }
 EXPORT_SYMBOL(fw_fill_response);