From dfd341e4e467d146901a3accb761f04fda535433 Mon Sep 17 00:00:00 2001 From: Jesse Brandeburg Date: Sat, 6 Jan 2007 09:51:38 -0800 Subject: [PATCH] ixgb: Maybe stop TX if not enough free descriptors A similar patch to commit 65c7973fa5b46b024f38be208aa477e8daf9a603 but now for ixgb. Cc: Herbert Xu Signed-off-by: Jesse Brandeburg Signed-off-by: Auke Kok --- drivers/net/ixgb/ixgb.h | 1 + drivers/net/ixgb/ixgb_ethtool.c | 1 + drivers/net/ixgb/ixgb_main.c | 37 ++++++++++++++++++++++++++++++--- 3 files changed, 36 insertions(+), 3 deletions(-) diff --git a/drivers/net/ixgb/ixgb.h b/drivers/net/ixgb/ixgb.h index 50ffe90488..f4aba4355b 100644 --- a/drivers/net/ixgb/ixgb.h +++ b/drivers/net/ixgb/ixgb.h @@ -171,6 +171,7 @@ struct ixgb_adapter { /* TX */ struct ixgb_desc_ring tx_ring ____cacheline_aligned_in_smp; + unsigned int restart_queue; unsigned long timeo_start; uint32_t tx_cmd_type; uint64_t hw_csum_tx_good; diff --git a/drivers/net/ixgb/ixgb_ethtool.c b/drivers/net/ixgb/ixgb_ethtool.c index cd22523fb0..82c044d6e0 100644 --- a/drivers/net/ixgb/ixgb_ethtool.c +++ b/drivers/net/ixgb/ixgb_ethtool.c @@ -79,6 +79,7 @@ static struct ixgb_stats ixgb_gstrings_stats[] = { {"tx_window_errors", IXGB_STAT(net_stats.tx_window_errors)}, {"tx_deferred_ok", IXGB_STAT(stats.dc)}, {"tx_timeout_count", IXGB_STAT(tx_timeout_count) }, + {"tx_restart_queue", IXGB_STAT(restart_queue) }, {"rx_long_length_errors", IXGB_STAT(stats.roc)}, {"rx_short_length_errors", IXGB_STAT(stats.ruc)}, #ifdef NETIF_F_TSO diff --git a/drivers/net/ixgb/ixgb_main.c b/drivers/net/ixgb/ixgb_main.c index 70ac9d4a83..16317b58f7 100644 --- a/drivers/net/ixgb/ixgb_main.c +++ b/drivers/net/ixgb/ixgb_main.c @@ -1411,6 +1411,37 @@ ixgb_tx_queue(struct ixgb_adapter *adapter, int count, int vlan_id,int tx_flags) IXGB_WRITE_REG(&adapter->hw, TDT, i); } +static int __ixgb_maybe_stop_tx(struct net_device *netdev, int size) +{ + struct ixgb_adapter *adapter = netdev_priv(netdev); + struct ixgb_desc_ring *tx_ring = &adapter->tx_ring; + + netif_stop_queue(netdev); + /* Herbert's original patch had: + * smp_mb__after_netif_stop_queue(); + * but since that doesn't exist yet, just open code it. */ + smp_mb(); + + /* We need to check again in a case another CPU has just + * made room available. */ + if (likely(IXGB_DESC_UNUSED(tx_ring) < size)) + return -EBUSY; + + /* A reprieve! */ + netif_start_queue(netdev); + ++adapter->restart_queue; + return 0; +} + +static int ixgb_maybe_stop_tx(struct net_device *netdev, + struct ixgb_desc_ring *tx_ring, int size) +{ + if (likely(IXGB_DESC_UNUSED(tx_ring) >= size)) + return 0; + return __ixgb_maybe_stop_tx(netdev, size); +} + + /* Tx Descriptors needed, worst case */ #define TXD_USE_COUNT(S) (((S) >> IXGB_MAX_TXD_PWR) + \ (((S) & (IXGB_MAX_DATA_PER_TXD - 1)) ? 1 : 0)) @@ -1444,7 +1475,8 @@ ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev) spin_lock_irqsave(&adapter->tx_lock, flags); #endif - if(unlikely(IXGB_DESC_UNUSED(&adapter->tx_ring) < DESC_NEEDED)) { + if (unlikely(ixgb_maybe_stop_tx(netdev, &adapter->tx_ring, + DESC_NEEDED))) { netif_stop_queue(netdev); spin_unlock_irqrestore(&adapter->tx_lock, flags); return NETDEV_TX_BUSY; @@ -1482,8 +1514,7 @@ ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev) #ifdef NETIF_F_LLTX /* Make sure there is space in the ring for the next send. */ - if(unlikely(IXGB_DESC_UNUSED(&adapter->tx_ring) < DESC_NEEDED)) - netif_stop_queue(netdev); + ixgb_maybe_stop_tx(netdev, &adapter->tx_ring, DESC_NEEDED); spin_unlock_irqrestore(&adapter->tx_lock, flags); -- 2.39.5