Commit c1056a59 authored by Michael Chan's avatar Michael Chan Committed by David S. Miller
Browse files

bnxt_en: Optimize xmit_more TX path 



Now that we use the cumulative consumer index scheme for TX completion,
we don't need to have one TX completion per TX packet in the xmit_more
code path.  Set the TX_BD_FLAGS_NO_CMPL flag if xmit_more is true.
Fallback to one interrupt per packet if the ring is filled beyond
bp->tx_wake_thresh.

Also, move the wmb() to bnxt_txr_db_kick().  When xmit_more is true,
we'll skip the bnxt_txr_db_kick() call and there is no need to call
wmb() to sync. the TX BD data.

Reviewed-by: default avatarSomnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: default avatarPavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: default avatarMichael Chan <michael.chan@broadcom.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ba098017

drivers/net/ethernet/broadcom/bnxt/bnxt.c

+10 −6
Original line number Diff line number Diff line
@@ -381,6 +381,8 @@ static u16 bnxt_xmit_get_cfa_action(struct sk_buff *skb) 
static void bnxt_txr_db_kick(struct bnxt *bp, struct bnxt_tx_ring_info *txr,

			     u16 prod)

{

	/* Sync BD data before updating doorbell */

	wmb();

	bnxt_db_write(bp, &txr->tx_db, prod);

	txr->kick_pending = 0;

}
@@ -388,7 +390,7 @@ static void bnxt_txr_db_kick(struct bnxt *bp, struct bnxt_tx_ring_info *txr, 
static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)

{

	struct bnxt *bp = netdev_priv(dev);

	struct tx_bd *txbd;

	struct tx_bd *txbd, *txbd0;

	struct tx_bd_ext *txbd1;

	struct netdev_queue *txq;

	int i;
@@ -602,6 +604,7 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	txbd1->tx_bd_cfa_meta = cpu_to_le32(vlan_tag_flags);

	txbd1->tx_bd_cfa_action =

			cpu_to_le32(cfa_action << TX_BD_CFA_ACTION_SHIFT);

	txbd0 = txbd;

	for (i = 0; i < last_frag; i++) {

		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
@@ -633,16 +636,17 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) 


	skb_tx_timestamp(skb);



	/* Sync BD data before updating doorbell */

	wmb();



	prod = NEXT_TX(prod);

	WRITE_ONCE(txr->tx_prod, prod);



	if (!netdev_xmit_more() || netif_xmit_stopped(txq))

	if (!netdev_xmit_more() || netif_xmit_stopped(txq)) {

		bnxt_txr_db_kick(bp, txr, prod);

	else

	} else {

		if (free_size >= bp->tx_wake_thresh)

			txbd0->tx_bd_len_flags_type |=

				cpu_to_le32(TX_BD_FLAGS_NO_CMPL);

		txr->kick_pending = 1;

	}



tx_done: