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 <edumazet@google.com>
Reported-by: Andy Cress <andy.cress@us.kontron.com>
Tested-by: Andy Cress <andy.cress@us.kontron.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2012-05-14 09:26:06 +00:00 committed by David S. Miller
parent 4e6304b842
commit 3ab77bf271
2 changed files with 11 additions and 16 deletions

View File

@ -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;

View File

@ -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;
}