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Commit 302d1252 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Jeff Garzik
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[PATCH] sky2: more conservative transmit locking 



Be more careful about transmit locking, this solves a possible race
between tx_complete and transmit, that would cause a tx timeout.

Signed-off-by: default avatarStephen Hemminger <shemminger@osdl.org>
Signed-off-by: default avatarJeff Garzik <jgarzik@pobox.com>
parent 28bd181a

drivers/net/sky2.c

+31 −12
Original line number Diff line number Diff line
@@ -889,13 +889,13 @@ static void sky2_vlan_rx_register(struct net_device *dev, struct vlan_group *grp 
	struct sky2_hw *hw = sky2->hw;

	u16 port = sky2->port;



	spin_lock(&sky2->tx_lock);

	spin_lock_bh(&sky2->tx_lock);



	sky2_write32(hw, SK_REG(port, RX_GMF_CTRL_T), RX_VLAN_STRIP_ON);

	sky2_write32(hw, SK_REG(port, TX_GMF_CTRL_T), TX_VLAN_TAG_ON);

	sky2->vlgrp = grp;



	spin_unlock(&sky2->tx_lock);

	spin_unlock_bh(&sky2->tx_lock);

}



static void sky2_vlan_rx_kill_vid(struct net_device *dev, unsigned short vid)
@@ -904,14 +904,14 @@ static void sky2_vlan_rx_kill_vid(struct net_device *dev, unsigned short vid) 
	struct sky2_hw *hw = sky2->hw;

	u16 port = sky2->port;



	spin_lock(&sky2->tx_lock);

	spin_lock_bh(&sky2->tx_lock);



	sky2_write32(hw, SK_REG(port, RX_GMF_CTRL_T), RX_VLAN_STRIP_OFF);

	sky2_write32(hw, SK_REG(port, TX_GMF_CTRL_T), TX_VLAN_TAG_OFF);

	if (sky2->vlgrp)

		sky2->vlgrp->vlan_devices[vid] = NULL;



	spin_unlock(&sky2->tx_lock);

	spin_unlock_bh(&sky2->tx_lock);

}

#endif
@@ -1116,6 +1116,10 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev) 
	u16 mss;

	u8 ctrl;



	/* No BH disabling for tx_lock here.  We are running in BH disabled

	 * context and TX reclaim runs via poll inside of a software

	 * interrupt, and no related locks in IRQ processing.

	 */

	if (!spin_trylock(&sky2->tx_lock))

		return NETDEV_TX_LOCKED;
@@ -1308,17 +1312,17 @@ static void sky2_tx_complete(struct sky2_port *sky2, u16 done) 
		dev_kfree_skb_any(skb);

	}



	spin_lock(&sky2->tx_lock);

	sky2->tx_cons = put;

	if (netif_queue_stopped(dev) && tx_avail(sky2) > MAX_SKB_TX_LE)

		netif_wake_queue(dev);

	spin_unlock(&sky2->tx_lock);

}



/* Cleanup all untransmitted buffers, assume transmitter not running */

static void sky2_tx_clean(struct sky2_port *sky2)

{

	spin_lock_bh(&sky2->tx_lock);

	sky2_tx_complete(sky2, sky2->tx_prod);

	spin_unlock_bh(&sky2->tx_lock);

}



/* Network shutdown */
@@ -1608,28 +1612,40 @@ static void sky2_phy_task(void *arg) 
	local_irq_enable();

}





/* Transmit timeout is only called if we are running, carries is up

 * and tx queue is full (stopped).

 */

static void sky2_tx_timeout(struct net_device *dev)

{

	struct sky2_port *sky2 = netdev_priv(dev);

	struct sky2_hw *hw = sky2->hw;

	unsigned txq = txqaddr[sky2->port];

	u16 ridx;



	/* Maybe we just missed an status interrupt */

	spin_lock(&sky2->tx_lock);

	ridx = sky2_read16(hw,

			   sky2->port == 0 ? STAT_TXA1_RIDX : STAT_TXA2_RIDX);

	sky2_tx_complete(sky2, ridx);

	spin_unlock(&sky2->tx_lock);



	if (!netif_queue_stopped(dev)) {

		if (net_ratelimit())

			pr_info(PFX "transmit interrupt missed? recovered\n");

		return;

	}



	if (netif_msg_timer(sky2))

		printk(KERN_ERR PFX "%s: tx timeout\n", dev->name);



	netif_stop_queue(dev);



	sky2_write32(hw, Q_ADDR(txq, Q_CSR), BMU_STOP);

	sky2_read32(hw, Q_ADDR(txq, Q_CSR));



	sky2_write32(hw, Y2_QADDR(txq, PREF_UNIT_CTRL), PREF_UNIT_RST_SET);



	sky2_tx_clean(sky2);



	sky2_qset(hw, txq);

	sky2_prefetch_init(hw, txq, sky2->tx_le_map, TX_RING_SIZE - 1);



	netif_wake_queue(dev);

}
@@ -1798,7 +1814,10 @@ static void sky2_tx_check(struct sky2_hw *hw, int port, u16 last) 
		struct net_device *dev = hw->dev[port];

		if (dev && netif_running(dev)) {

			struct sky2_port *sky2 = netdev_priv(dev);



			spin_lock(&sky2->tx_lock);

			sky2_tx_complete(sky2, last);

			spin_unlock(&sky2->tx_lock);

		}

	}

}