From 3ab77bf271e6a41512e366dfa5110edb981ed1d3 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 14 May 2012 09:26:06 +0000 Subject: [PATCH] pch_gbe: fix transmit races Andy reported pch_gbe triggered "NETDEV WATCHDOG" errors. May 11 11:06:09 kontron kernel: WARNING: at net/sched/sch_generic.c:261 dev_watchdog+0x1ec/0x200() (Not tainted) May 11 11:06:09 kontron kernel: Hardware name: N/A May 11 11:06:09 kontron kernel: NETDEV WATCHDOG: eth0 (pch_gbe): transmit queue 0 timed out It seems pch_gbe has a racy tx path (races with TX completion path) Remove tx_queue_lock lock since it has no purpose, we must use tx_lock instead. Signed-off-by: Eric Dumazet Reported-by: Andy Cress Tested-by: Andy Cress Signed-off-by: David S. Miller --- .../net/ethernet/oki-semi/pch_gbe/pch_gbe.h | 2 -- .../ethernet/oki-semi/pch_gbe/pch_gbe_main.c | 25 ++++++++----------- 2 files changed, 11 insertions(+), 16 deletions(-) diff --git a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe.h b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe.h index dd14915f54bb..ba781747d174 100644 --- a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe.h +++ b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe.h @@ -584,7 +584,6 @@ struct pch_gbe_hw_stats { /** * struct pch_gbe_adapter - board specific private data structure * @stats_lock: Spinlock structure for status - * @tx_queue_lock: Spinlock structure for transmit * @ethtool_lock: Spinlock structure for ethtool * @irq_sem: Semaphore for interrupt * @netdev: Pointer of network device structure @@ -609,7 +608,6 @@ struct pch_gbe_hw_stats { struct pch_gbe_adapter { spinlock_t stats_lock; - spinlock_t tx_queue_lock; spinlock_t ethtool_lock; atomic_t irq_sem; struct net_device *netdev; diff --git a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c index 8035e5ff6e06..1e38d502a062 100644 --- a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c +++ b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c @@ -640,14 +640,11 @@ static void pch_gbe_mac_set_pause_packet(struct pch_gbe_hw *hw) */ static int pch_gbe_alloc_queues(struct pch_gbe_adapter *adapter) { - int size; - - size = (int)sizeof(struct pch_gbe_tx_ring); - adapter->tx_ring = kzalloc(size, GFP_KERNEL); + adapter->tx_ring = kzalloc(sizeof(*adapter->tx_ring), GFP_KERNEL); if (!adapter->tx_ring) return -ENOMEM; - size = (int)sizeof(struct pch_gbe_rx_ring); - adapter->rx_ring = kzalloc(size, GFP_KERNEL); + + adapter->rx_ring = kzalloc(sizeof(*adapter->rx_ring), GFP_KERNEL); if (!adapter->rx_ring) { kfree(adapter->tx_ring); return -ENOMEM; @@ -1162,7 +1159,6 @@ static void pch_gbe_tx_queue(struct pch_gbe_adapter *adapter, struct sk_buff *tmp_skb; unsigned int frame_ctrl; unsigned int ring_num; - unsigned long flags; /*-- Set frame control --*/ frame_ctrl = 0; @@ -1211,14 +1207,14 @@ static void pch_gbe_tx_queue(struct pch_gbe_adapter *adapter, } } } - spin_lock_irqsave(&tx_ring->tx_lock, flags); + ring_num = tx_ring->next_to_use; if (unlikely((ring_num + 1) == tx_ring->count)) tx_ring->next_to_use = 0; else tx_ring->next_to_use = ring_num + 1; - spin_unlock_irqrestore(&tx_ring->tx_lock, flags); + buffer_info = &tx_ring->buffer_info[ring_num]; tmp_skb = buffer_info->skb; @@ -1518,7 +1514,7 @@ pch_gbe_alloc_rx_buffers_pool(struct pch_gbe_adapter *adapter, &rx_ring->rx_buff_pool_logic, GFP_KERNEL); if (!rx_ring->rx_buff_pool) { - pr_err("Unable to allocate memory for the receive poll buffer\n"); + pr_err("Unable to allocate memory for the receive pool buffer\n"); return -ENOMEM; } memset(rx_ring->rx_buff_pool, 0, size); @@ -1637,15 +1633,17 @@ pch_gbe_clean_tx(struct pch_gbe_adapter *adapter, pr_debug("called pch_gbe_unmap_and_free_tx_resource() %d count\n", cleaned_count); /* Recover from running out of Tx resources in xmit_frame */ + spin_lock(&tx_ring->tx_lock); if (unlikely(cleaned && (netif_queue_stopped(adapter->netdev)))) { netif_wake_queue(adapter->netdev); adapter->stats.tx_restart_count++; pr_debug("Tx wake queue\n"); } - spin_lock(&adapter->tx_queue_lock); + tx_ring->next_to_clean = i; - spin_unlock(&adapter->tx_queue_lock); + pr_debug("next_to_clean : %d\n", tx_ring->next_to_clean); + spin_unlock(&tx_ring->tx_lock); return cleaned; } @@ -2037,7 +2035,6 @@ static int pch_gbe_sw_init(struct pch_gbe_adapter *adapter) return -ENOMEM; } spin_lock_init(&adapter->hw.miim_lock); - spin_lock_init(&adapter->tx_queue_lock); spin_lock_init(&adapter->stats_lock); spin_lock_init(&adapter->ethtool_lock); atomic_set(&adapter->irq_sem, 0); @@ -2142,10 +2139,10 @@ static int pch_gbe_xmit_frame(struct sk_buff *skb, struct net_device *netdev) tx_ring->next_to_use, tx_ring->next_to_clean); return NETDEV_TX_BUSY; } - spin_unlock_irqrestore(&tx_ring->tx_lock, flags); /* CRC,ITAG no support */ pch_gbe_tx_queue(adapter, tx_ring, skb); + spin_unlock_irqrestore(&tx_ring->tx_lock, flags); return NETDEV_TX_OK; }