From 7a9905e64272c8021a8cfaf6015dd0fb8eeeb378 Mon Sep 17 00:00:00 2001 From: Rajesh Borundia Date: Mon, 18 Oct 2010 02:03:41 +0000 Subject: [PATCH] netxen: fix race in tx stop queue There is race between netif_stop_queue and netif_stopped_queue check.So check once again if buffers are available to avoid race. With above logic we can also get rid of tx lock in process_cmd_ring. Signed-off-by: Rajesh Borundia Signed-off-by: Amit Kumar Salecha Signed-off-by: David S. Miller --- drivers/net/netxen/netxen_nic.h | 5 ++++- drivers/net/netxen/netxen_nic_hw.c | 10 ++++++++-- drivers/net/netxen/netxen_nic_init.c | 10 +++------- drivers/net/netxen/netxen_nic_main.c | 15 +++++++-------- 4 files changed, 22 insertions(+), 18 deletions(-) diff --git a/drivers/net/netxen/netxen_nic.h b/drivers/net/netxen/netxen_nic.h index 6dca357..92f89af 100644 --- a/drivers/net/netxen/netxen_nic.h +++ b/drivers/net/netxen/netxen_nic.h @@ -175,7 +175,10 @@ #define MAX_NUM_CARDS 4 #define MAX_BUFFERS_PER_CMD 32 -#define TX_STOP_THRESH ((MAX_SKB_FRAGS >> 2) + 4) +#define MAX_TSO_HEADER_DESC 2 +#define MGMT_CMD_DESC_RESV 4 +#define TX_STOP_THRESH ((MAX_SKB_FRAGS >> 2) + MAX_TSO_HEADER_DESC \ + + MGMT_CMD_DESC_RESV) #define NX_MAX_TX_TIMEOUTS 2 /* diff --git a/drivers/net/netxen/netxen_nic_hw.c b/drivers/net/netxen/netxen_nic_hw.c index 29d7b93..10e2f13 100644 --- a/drivers/net/netxen/netxen_nic_hw.c +++ b/drivers/net/netxen/netxen_nic_hw.c @@ -598,8 +598,14 @@ netxen_send_cmd_descs(struct netxen_adapter *adapter, if (nr_desc >= netxen_tx_avail(tx_ring)) { netif_tx_stop_queue(tx_ring->txq); - __netif_tx_unlock_bh(tx_ring->txq); - return -EBUSY; + smp_mb(); + if (netxen_tx_avail(tx_ring) > nr_desc) { + if (netxen_tx_avail(tx_ring) > TX_STOP_THRESH) + netif_tx_wake_queue(tx_ring->txq); + } else { + __netif_tx_unlock_bh(tx_ring->txq); + return -EBUSY; + } } do { diff --git a/drivers/net/netxen/netxen_nic_init.c b/drivers/net/netxen/netxen_nic_init.c index a2d805a..95fe552 100644 --- a/drivers/net/netxen/netxen_nic_init.c +++ b/drivers/net/netxen/netxen_nic_init.c @@ -1763,14 +1763,10 @@ int netxen_process_cmd_ring(struct netxen_adapter *adapter) smp_mb(); - if (netif_queue_stopped(netdev) && netif_carrier_ok(netdev)) { - __netif_tx_lock(tx_ring->txq, smp_processor_id()); - if (netxen_tx_avail(tx_ring) > TX_STOP_THRESH) { + if (netif_queue_stopped(netdev) && netif_carrier_ok(netdev)) + if (netxen_tx_avail(tx_ring) > TX_STOP_THRESH) netif_wake_queue(netdev); - adapter->tx_timeo_cnt = 0; - } - __netif_tx_unlock(tx_ring->txq); - } + adapter->tx_timeo_cnt = 0; } /* * If everything is freed up to consumer then check if the ring is full diff --git a/drivers/net/netxen/netxen_nic_main.c b/drivers/net/netxen/netxen_nic_main.c index 2c6ceeb..83ee554 100644 --- a/drivers/net/netxen/netxen_nic_main.c +++ b/drivers/net/netxen/netxen_nic_main.c @@ -125,11 +125,6 @@ netxen_nic_update_cmd_producer(struct netxen_adapter *adapter, struct nx_host_tx_ring *tx_ring) { NXWRIO(adapter, tx_ring->crb_cmd_producer, tx_ring->producer); - - if (netxen_tx_avail(tx_ring) <= TX_STOP_THRESH) { - netif_stop_queue(adapter->netdev); - smp_mb(); - } } static uint32_t crb_cmd_consumer[4] = { @@ -1209,7 +1204,7 @@ netxen_setup_netdev(struct netxen_adapter *adapter, adapter->max_mc_count = 16; netdev->netdev_ops = &netxen_netdev_ops; - netdev->watchdog_timeo = 2*HZ; + netdev->watchdog_timeo = 5*HZ; netxen_nic_change_mtu(netdev, netdev->mtu); @@ -1825,9 +1820,13 @@ netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev) /* 4 fragments per cmd des */ no_of_desc = (frag_count + 3) >> 2; - if (unlikely(no_of_desc + 2 > netxen_tx_avail(tx_ring))) { + if (unlikely(netxen_tx_avail(tx_ring) <= TX_STOP_THRESH)) { netif_stop_queue(netdev); - return NETDEV_TX_BUSY; + smp_mb(); + if (netxen_tx_avail(tx_ring) > TX_STOP_THRESH) + netif_start_queue(netdev); + else + return NETDEV_TX_BUSY; } producer = tx_ring->producer; -- 2.7.4