Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3ab77bf2 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

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: default avatarEric Dumazet <edumazet@google.com>
Reported-by: default avatarAndy Cress <andy.cress@us.kontron.com>
Tested-by: default avatarAndy Cress <andy.cress@us.kontron.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4e6304b8

drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe.h

+0 −2
Original line number Diff line number Diff line
@@ -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;

drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c

+11 −14
Original line number Diff line number Diff line
@@ -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;

}