Commit dfd341e4 authored by Jesse Brandeburg's avatar Jesse Brandeburg Committed by Auke Kok
Browse files

ixgb: Maybe stop TX if not enough free descriptors 



A similar patch to commit 65c7973f
but now for ixgb.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: default avatarAuke Kok <auke-jan.h.kok@intel.com>
parent 5d927853

drivers/net/ixgb/ixgb.h

+1 −0
Original line number Diff line number Diff line
@@ -171,6 +171,7 @@ struct ixgb_adapter { 


	/* TX */

	struct ixgb_desc_ring tx_ring ____cacheline_aligned_in_smp;

	unsigned int restart_queue;

	unsigned long timeo_start;

	uint32_t tx_cmd_type;

	uint64_t hw_csum_tx_good;

drivers/net/ixgb/ixgb_ethtool.c

+1 −0
Original line number Diff line number Diff line
@@ -79,6 +79,7 @@ static struct ixgb_stats ixgb_gstrings_stats[] = { 
	{"tx_window_errors", IXGB_STAT(net_stats.tx_window_errors)},

	{"tx_deferred_ok", IXGB_STAT(stats.dc)},

	{"tx_timeout_count", IXGB_STAT(tx_timeout_count) },

	{"tx_restart_queue", IXGB_STAT(restart_queue) },

	{"rx_long_length_errors", IXGB_STAT(stats.roc)},

	{"rx_short_length_errors", IXGB_STAT(stats.ruc)},

#ifdef NETIF_F_TSO

drivers/net/ixgb/ixgb_main.c

+34 −3
Original line number Diff line number Diff line
@@ -1411,6 +1411,37 @@ ixgb_tx_queue(struct ixgb_adapter *adapter, int count, int vlan_id,int tx_flags) 
	IXGB_WRITE_REG(&adapter->hw, TDT, i);

}



static int __ixgb_maybe_stop_tx(struct net_device *netdev, int size)

{

	struct ixgb_adapter *adapter = netdev_priv(netdev);

	struct ixgb_desc_ring *tx_ring = &adapter->tx_ring;



	netif_stop_queue(netdev);

	/* Herbert's original patch had:

	 *  smp_mb__after_netif_stop_queue();

	 * but since that doesn't exist yet, just open code it. */

	smp_mb();



	/* We need to check again in a case another CPU has just

	 * made room available. */

	if (likely(IXGB_DESC_UNUSED(tx_ring) < size))

		return -EBUSY;



	/* A reprieve! */

	netif_start_queue(netdev);

	++adapter->restart_queue;

	return 0;

}



static int ixgb_maybe_stop_tx(struct net_device *netdev,

                              struct ixgb_desc_ring *tx_ring, int size)

{

	if (likely(IXGB_DESC_UNUSED(tx_ring) >= size))

		return 0;

	return __ixgb_maybe_stop_tx(netdev, size);

}





/* Tx Descriptors needed, worst case */

#define TXD_USE_COUNT(S) (((S) >> IXGB_MAX_TXD_PWR) + \

			 (((S) & (IXGB_MAX_DATA_PER_TXD - 1)) ? 1 : 0))
@@ -1444,7 +1475,8 @@ ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev) 
	spin_lock_irqsave(&adapter->tx_lock, flags);

#endif



	if(unlikely(IXGB_DESC_UNUSED(&adapter->tx_ring) < DESC_NEEDED)) {

	if (unlikely(ixgb_maybe_stop_tx(netdev, &adapter->tx_ring,

                     DESC_NEEDED))) {

		netif_stop_queue(netdev);

		spin_unlock_irqrestore(&adapter->tx_lock, flags);

		return NETDEV_TX_BUSY;
@@ -1482,8 +1514,7 @@ ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev) 


#ifdef NETIF_F_LLTX

	/* Make sure there is space in the ring for the next send. */

	if(unlikely(IXGB_DESC_UNUSED(&adapter->tx_ring) < DESC_NEEDED))

		netif_stop_queue(netdev);

	ixgb_maybe_stop_tx(netdev, &adapter->tx_ring, DESC_NEEDED);



	spin_unlock_irqrestore(&adapter->tx_lock, flags);