[PATCH v2 net 1/9] net: enetc: fix the off-by-one issue in enetc_map_tx_buffs()

[Wei Fang <wei.fang@nxp.com>]

When a DMA mapping error occurs while processing skb frags, it will free
one more tx_swbd than expected, so fix this off-by-one issue.

Fixes: d4fd0404c1c9 ("enetc: Introduce basic PF and VF ENETC ethernet drivers")
Cc: stable@vger.kernel.org
Signed-off-by: Wei Fang <wei.fang@nxp.com>
---
 drivers/net/ethernet/freescale/enetc/enetc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index 6a6fc819dfde..01c09fd26f9f 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -372,13 +372,13 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb)
 dma_err:
 	dev_err(tx_ring->dev, "DMA map error");
 
-	do {
+	while (count--) {
 		tx_swbd = &tx_ring->tx_swbd[i];
 		enetc_free_tx_frame(tx_ring, tx_swbd);
 		if (i == 0)
 			i = tx_ring->bd_count;
 		i--;
-	} while (count--);
+	}
 
 	return 0;
 }
-- 
2.34.1