[PATCH net-next] net: fec: implement TSO descriptor cleanup

[Dheeraj Reddy Jonnalagadda <dheeraj.linuxdev@gmail.com>]

Implement the TODO in fec_enet_txq_submit_tso() error path to properly
release buffer descriptors that were allocated during a failed TSO
operation. This prevents descriptor leaks when TSO operations fail
partway through.

The cleanup iterates from the starting descriptor to where the error
occurred, resetting the status and buffer address fields of each
descriptor.

Signed-off-by: Dheeraj Reddy Jonnalagadda <dheeraj.linuxdev@gmail.com>
---
 drivers/net/ethernet/freescale/fec_main.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index b2daed55bf6c..eff065010c9e 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -913,7 +913,18 @@ static int fec_enet_txq_submit_tso(struct fec_enet_priv_tx_q *txq,
 	return 0;
 
 err_release:
-	/* TODO: Release all used data descriptors for TSO */
+	/* Release all used data descriptors for TSO */
+	struct bufdesc *tmp_bdp = txq->bd.cur;
+
+	while (tmp_bdp != bdp) {
+		tmp_bdp->cbd_sc = 0;
+		tmp_bdp->cbd_bufaddr = 0;
+		tmp_bdp->cbd_datlen = 0;
+		tmp_bdp = fec_enet_get_nextdesc(tmp_bdp, &txq->bd);
+	}
+
+	dev_kfree_skb_any(skb);
+
 	return ret;
 }
 
-- 
2.34.1