From: Michael Chan <michael.chan@xxxxxxxxxxxx>
[ Upstream commit 5bed8b0704c9ecccc8f4a2c377d7c8e21090a82e ]
The smallest TX ring size we support must fit a TX SKB with MAX_SKB_FRAGS
+ 1. Because the first TX BD for a packet is always a long TX BD, we
need an extra TX BD to fit this packet. Define BNXT_MIN_TX_DESC_CNT with
this value to make this more clear. The current code uses a minimum
that is off by 1. Fix it using this constant.
The tx_wake_thresh to determine when to wake up the TX queue is half the
ring size but we must have at least BNXT_MIN_TX_DESC_CNT for the next
packet which may have maximum fragments. So the comparison of the
available TX BDs with tx_wake_thresh should be >= instead of > in the
current code. Otherwise, at the smallest ring size, we will never wake
up the TX queue and will cause TX timeout.
Fixes: c0c050c58d84 ("bnxt_en: New Broadcom ethernet driver.")
Reviewed-by: Pavan Chebbi <pavan.chebbi@xxxxxxxxxxxx>
Signed-off-by: Michael Chan <michael.chan@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 8 ++++----
drivers/net/ethernet/broadcom/bnxt/bnxt.h | 5 +++++
drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 2 +-
3 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index fdbf47446a99..f20b57b8cd70 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -385,7 +385,7 @@ static bool bnxt_txr_netif_try_stop_queue(struct bnxt *bp,
* netif_tx_queue_stopped().
*/
smp_mb();
- if (bnxt_tx_avail(bp, txr) > bp->tx_wake_thresh) {
+ if (bnxt_tx_avail(bp, txr) >= bp->tx_wake_thresh) {
netif_tx_wake_queue(txq);
return false;
}
@@ -758,7 +758,7 @@ static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts)
smp_mb();
if (unlikely(netif_tx_queue_stopped(txq)) &&
- bnxt_tx_avail(bp, txr) > bp->tx_wake_thresh &&
+ bnxt_tx_avail(bp, txr) >= bp->tx_wake_thresh &&
READ_ONCE(txr->dev_state) != BNXT_DEV_STATE_CLOSING)
netif_tx_wake_queue(txq);
}
@@ -2375,7 +2375,7 @@ static int __bnxt_poll_work(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
if (TX_CMP_TYPE(txcmp) == CMP_TYPE_TX_L2_CMP) {
tx_pkts++;
/* return full budget so NAPI will complete. */
- if (unlikely(tx_pkts > bp->tx_wake_thresh)) {
+ if (unlikely(tx_pkts >= bp->tx_wake_thresh)) {
rx_pkts = budget;
raw_cons = NEXT_RAW_CMP(raw_cons);
if (budget)
@@ -3531,7 +3531,7 @@ static int bnxt_init_tx_rings(struct bnxt *bp)
u16 i;
bp->tx_wake_thresh = max_t(int, bp->tx_ring_size / 2,
- MAX_SKB_FRAGS + 1);
+ BNXT_MIN_TX_DESC_CNT);
for (i = 0; i < bp->tx_nr_rings; i++) {
struct bnxt_tx_ring_info *txr = &bp->tx_ring[i];
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index ba4e0fc38520..d4dca4508d26 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -615,6 +615,11 @@ struct nqe_cn {
#define BNXT_MAX_RX_JUM_DESC_CNT (RX_DESC_CNT * MAX_RX_AGG_PAGES - 1)
#define BNXT_MAX_TX_DESC_CNT (TX_DESC_CNT * MAX_TX_PAGES - 1)
+/* Minimum TX BDs for a TX packet with MAX_SKB_FRAGS + 1. We need one extra
+ * BD because the first TX BD is always a long BD.
+ */
+#define BNXT_MIN_TX_DESC_CNT (MAX_SKB_FRAGS + 2)
+
#define RX_RING(x) (((x) & ~(RX_DESC_CNT - 1)) >> (BNXT_PAGE_SHIFT - 4))
#define RX_IDX(x) ((x) & (RX_DESC_CNT - 1))
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index 786ca51e669b..3a8c28463592 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -784,7 +784,7 @@ static int bnxt_set_ringparam(struct net_device *dev,
if ((ering->rx_pending > BNXT_MAX_RX_DESC_CNT) ||
(ering->tx_pending > BNXT_MAX_TX_DESC_CNT) ||
- (ering->tx_pending <= MAX_SKB_FRAGS))
+ (ering->tx_pending < BNXT_MIN_TX_DESC_CNT))
return -EINVAL;
if (netif_running(dev))
--
2.33.0
