sfc: Fix DMA mapping cleanup in case of an error in TSO

We need buffer->len to remain valid to work out the correct address to
be unmapped.  We therefore need to clear buffer->len after the unmap
operation.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/net/sfc/tx.c b/drivers/net/sfc/tx.c
index e669f94e821b..a8b70ef6d817 100644
--- a/drivers/net/sfc/tx.c
+++ b/drivers/net/sfc/tx.c
@@ -821,8 +821,6 @@ static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue)
                                            EFX_TXQ_MASK];
                 efx_tsoh_free(tx_queue, buffer);
                 EFX_BUG_ON_PARANOID(buffer->skb);
-                buffer->len = 0;
-                buffer->continuation = true;
                 if (buffer->unmap_len) {
                         unmap_addr = (buffer->dma_addr + buffer->len -
                                       buffer->unmap_len);
@@ -836,6 +834,8 @@ static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue)
                                                PCI_DMA_TODEVICE);
                         buffer->unmap_len = 0;
                 }
+                buffer->len = 0;
+                buffer->continuation = true;
         }
 }