From: Michael Chan michael.chan@broadcom.com
[ 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@broadcom.com Signed-off-by: Michael Chan michael.chan@broadocm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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 26179e437bbf..cb0c270418a4 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -381,7 +381,7 @@ 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; } @@ -717,7 +717,7 @@ 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); } @@ -2300,7 +2300,7 @@ 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) @@ -3431,7 +3431,7 @@ 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 95d10e7bbb04..92f9f7f5240b 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h @@ -611,6 +611,11 @@ 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 1471c9a36238..6f9196ff2ac4 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c @@ -780,7 +780,7 @@ 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))