From daf6edc3174b090cae59e226206511428629aaa0 Mon Sep 17 00:00:00 2001 From: Chengwen Feng Date: Mon, 5 Sep 2022 16:59:34 +0800 Subject: [PATCH] net/hns3: fix next-to-use overflow in simple Tx [ upstream commit 76a9c980cf61d8ee21402d1d1d650d2f9d49cfb0 ] If txq's next-to-use plus nb_pkts equal txq's nb_tx_desc when using simple xmit algorithm, the txq's next-to-use will equal nb_tx_desc fter the xmit, this does not cause Tx exceptions, but may affect other ops that depend on this field, such as tx_descriptor_status. Fixes: 7ef933908f04 ("net/hns3: add simple Tx path") Signed-off-by: Chengwen Feng Signed-off-by: Dongdong Liu --- drivers/net/hns3/hns3_rxtx.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/net/hns3/hns3_rxtx.c b/drivers/net/hns3/hns3_rxtx.c index 403f811a51..49b116c1b8 100644 --- a/drivers/net/hns3/hns3_rxtx.c +++ b/drivers/net/hns3/hns3_rxtx.c @@ -4137,14 +4137,16 @@ hns3_xmit_pkts_simple(void *tx_queue, } txq->tx_bd_ready -= nb_pkts; - if (txq->next_to_use + nb_pkts > txq->nb_tx_desc) { + if (txq->next_to_use + nb_pkts >= txq->nb_tx_desc) { nb_tx = txq->nb_tx_desc - txq->next_to_use; hns3_tx_fill_hw_ring(txq, tx_pkts, nb_tx); txq->next_to_use = 0; } - hns3_tx_fill_hw_ring(txq, tx_pkts + nb_tx, nb_pkts - nb_tx); - txq->next_to_use += nb_pkts - nb_tx; + if (nb_pkts > nb_tx) { + hns3_tx_fill_hw_ring(txq, tx_pkts + nb_tx, nb_pkts - nb_tx); + txq->next_to_use += nb_pkts - nb_tx; + } hns3_write_txq_tail_reg(txq, nb_pkts);