From ef71ff833acfd3795c3af1bb800ac186561508ef Mon Sep 17 00:00:00 2001 From: Rajesh K Borundia Date: Thu, 17 Jun 2010 02:56:41 +0000 Subject: [PATCH] qlcnic: fix race in tx stop queue There is a 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 K Borundia Signed-off-by: Amit Kumar Salecha Signed-off-by: David S. Miller --- drivers/net/qlcnic/qlcnic.h | 8 +++++--- drivers/net/qlcnic/qlcnic_hw.c | 12 +++++++++--- drivers/net/qlcnic/qlcnic_init.c | 2 ++ drivers/net/qlcnic/qlcnic_main.c | 23 ++++++++++------------- 4 files changed, 26 insertions(+), 19 deletions(-) diff --git a/drivers/net/qlcnic/qlcnic.h b/drivers/net/qlcnic/qlcnic.h index 9970cff598d1..99ccdd8ac419 100644 --- a/drivers/net/qlcnic/qlcnic.h +++ b/drivers/net/qlcnic/qlcnic.h @@ -113,8 +113,10 @@ #define TX_UDPV6_PKT 0x0c /* Tx defines */ -#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 QLCNIC_MAX_TX_TIMEOUTS 2 /* @@ -369,7 +371,7 @@ struct qlcnic_recv_crb { */ struct qlcnic_cmd_buffer { struct sk_buff *skb; - struct qlcnic_skb_frag frag_array[MAX_BUFFERS_PER_CMD + 1]; + struct qlcnic_skb_frag frag_array[MAX_SKB_FRAGS + 1]; u32 frag_count; }; diff --git a/drivers/net/qlcnic/qlcnic_hw.c b/drivers/net/qlcnic/qlcnic_hw.c index f776956d2d6c..d9becb96d403 100644 --- a/drivers/net/qlcnic/qlcnic_hw.c +++ b/drivers/net/qlcnic/qlcnic_hw.c @@ -338,9 +338,15 @@ qlcnic_send_cmd_descs(struct qlcnic_adapter *adapter, if (nr_desc >= qlcnic_tx_avail(tx_ring)) { netif_tx_stop_queue(tx_ring->txq); - __netif_tx_unlock_bh(tx_ring->txq); - adapter->stats.xmit_off++; - return -EBUSY; + smp_mb(); + if (qlcnic_tx_avail(tx_ring) > nr_desc) { + if (qlcnic_tx_avail(tx_ring) > TX_STOP_THRESH) + netif_tx_wake_queue(tx_ring->txq); + } else { + adapter->stats.xmit_off++; + __netif_tx_unlock_bh(tx_ring->txq); + return -EBUSY; + } } do { diff --git a/drivers/net/qlcnic/qlcnic_init.c b/drivers/net/qlcnic/qlcnic_init.c index 2bd00d54dd3f..058ce61501c3 100644 --- a/drivers/net/qlcnic/qlcnic_init.c +++ b/drivers/net/qlcnic/qlcnic_init.c @@ -181,7 +181,9 @@ skip_rds: tx_ring = adapter->tx_ring; vfree(tx_ring->cmd_buf_arr); + tx_ring->cmd_buf_arr = NULL; kfree(adapter->tx_ring); + adapter->tx_ring = NULL; } int qlcnic_alloc_sw_resources(struct qlcnic_adapter *adapter) diff --git a/drivers/net/qlcnic/qlcnic_main.c b/drivers/net/qlcnic/qlcnic_main.c index 06d2dfd646fe..655bccd7f8f4 100644 --- a/drivers/net/qlcnic/qlcnic_main.c +++ b/drivers/net/qlcnic/qlcnic_main.c @@ -132,12 +132,6 @@ qlcnic_update_cmd_producer(struct qlcnic_adapter *adapter, struct qlcnic_host_tx_ring *tx_ring) { writel(tx_ring->producer, tx_ring->crb_cmd_producer); - - if (qlcnic_tx_avail(tx_ring) <= TX_STOP_THRESH) { - netif_stop_queue(adapter->netdev); - smp_mb(); - adapter->stats.xmit_off++; - } } static const u32 msi_tgt_status[8] = { @@ -1137,7 +1131,7 @@ qlcnic_setup_netdev(struct qlcnic_adapter *adapter, adapter->max_mc_count = 38; netdev->netdev_ops = &qlcnic_netdev_ops; - netdev->watchdog_timeo = 2*HZ; + netdev->watchdog_timeo = 5*HZ; qlcnic_change_mtu(netdev, netdev->mtu); @@ -1709,10 +1703,15 @@ qlcnic_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 > qlcnic_tx_avail(tx_ring))) { + if (unlikely(qlcnic_tx_avail(tx_ring) <= TX_STOP_THRESH)) { netif_stop_queue(netdev); - adapter->stats.xmit_off++; - return NETDEV_TX_BUSY; + smp_mb(); + if (qlcnic_tx_avail(tx_ring) > TX_STOP_THRESH) + netif_start_queue(netdev); + else { + adapter->stats.xmit_off++; + return NETDEV_TX_BUSY; + } } producer = tx_ring->producer; @@ -2018,14 +2017,12 @@ static int qlcnic_process_cmd_ring(struct qlcnic_adapter *adapter) smp_mb(); if (netif_queue_stopped(netdev) && netif_carrier_ok(netdev)) { - __netif_tx_lock(tx_ring->txq, smp_processor_id()); if (qlcnic_tx_avail(tx_ring) > TX_STOP_THRESH) { netif_wake_queue(netdev); - adapter->tx_timeo_cnt = 0; adapter->stats.xmit_on++; } - __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 -- 2.20.1