[PATCH 12/13] net: thunderx: Fix for duplicate CQEs by HW for TSO packets

From: Sunil Goutham
Date: Mon Nov 30 2015 - 13:18:33 EST


From: Sunil Goutham <sgoutham@xxxxxxxxxx>

HW sends a CQE for each segment of a TSO packet instead of a single CQE
for whole TSO packet transmitted. Each of this CQE points to the same SQE.
SW should takecare of not freeing same SQE multiple times.

Signed-off-by: Sunil Goutham <sgoutham@xxxxxxxxxx>
---
drivers/net/ethernet/cavium/thunder/nicvf_main.c | 10 ++++++++--
1 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
index 51bbe67..a75f21f 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
@@ -525,14 +525,20 @@ static void nicvf_snd_pkt_handler(struct net_device *netdev,
__func__, cqe_tx->sq_qs, cqe_tx->sq_idx,
cqe_tx->sqe_ptr, hdr->subdesc_cnt);

- nicvf_put_sq_desc(sq, hdr->subdesc_cnt + 1);
nicvf_check_cqe_tx_errs(nic, cq, cqe_tx);
skb = (struct sk_buff *)sq->skbuff[cqe_tx->sqe_ptr];
- /* For TSO offloaded packets only one head SKB needs to be freed */
+ /* For SW TSO offloaded packets only one head SKB needs to be freed */
if (skb) {
+ nicvf_put_sq_desc(sq, hdr->subdesc_cnt + 1);
prefetch(skb);
dev_consume_skb_any(skb);
sq->skbuff[cqe_tx->sqe_ptr] = (u64)NULL;
+ } else {
+ /* In case of HW TSO, a CQE_TX is added by HW for each segment.
+ * Free SQEs only once.
+ */
+ if (!nic->hw_tso)
+ nicvf_put_sq_desc(sq, hdr->subdesc_cnt + 1);
}
}

--
1.7.1

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