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 Signed-off-by: Michael Chan --- 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 037767b370d5..62f84cc91e4d 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -391,7 +391,7 @@ 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; } @@ -764,7 +764,7 @@ 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); } @@ -2416,7 +2416,7 @@ 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) @@ -3640,7 +3640,7 @@ 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 ec046e7a2484..19fe6478e9b4 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h @@ -629,6 +629,11 @@ 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 b056e3c29bbd..7260910e75fb 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c @@ -798,7 +798,7 @@ 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)) -- 2.18.1