[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: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index f03bf79c..0c7665e 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -889,13 +889,13 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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);
}
}
}