forcedeth: tx timeout fix

This patch fixes the tx_timeout() to properly handle the clean up of the
tx ring. It also sets the tx put pointer back to the correct position to
be in sync with HW.

Signed-off-by: Ayaz Abdulla <aabdulla@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 10 deletions

diff --git a/drivers/net/forcedeth.c b/drivers/net/forcedeth.c
index 11d5db16ed9..f9a846b1b92 100644
--- a/drivers/net/forcedeth.c
+++ b/drivers/net/forcedeth.c
@@ -1880,6 +1880,7 @@ static void nv_init_tx(struct net_device *dev)
         np->tx_pkts_in_progress = 0;
         np->tx_change_owner = NULL;
         np->tx_end_flip = NULL;
+        np->tx_stop = 0;
 
         for (i = 0; i < np->tx_ring_size; i++) {
                 if (!nv_optimized(np)) {
@@ -2530,6 +2531,8 @@ static void nv_tx_timeout(struct net_device *dev)
         struct fe_priv *np = netdev_priv(dev);
         u8 __iomem *base = get_hwbase(dev);
         u32 status;
+        union ring_type put_tx;
+        int saved_tx_limit;
 
         if (np->msi_flags & NV_MSI_X_ENABLED)
                 status = readl(base + NvRegMSIXIrqStatus) & NVREG_IRQSTAT_MASK;
@@ -2589,24 +2592,32 @@ static void nv_tx_timeout(struct net_device *dev)
         /* 1) stop tx engine */
         nv_stop_tx(dev);
 
-        /* 2) check that the packets were not sent already: */
+        /* 2) complete any outstanding tx and do not give HW any limited tx pkts */
+        saved_tx_limit = np->tx_limit;
+        np->tx_limit = 0; /* prevent giving HW any limited pkts */
+        np->tx_stop = 0;  /* prevent waking tx queue */
         if (!nv_optimized(np))
                 nv_tx_done(dev, np->tx_ring_size);
         else
                 nv_tx_done_optimized(dev, np->tx_ring_size);
 
-        /* 3) if there are dead entries: clear everything */
-        if (np->get_tx_ctx != np->put_tx_ctx) {
-                printk(KERN_DEBUG "%s: tx_timeout: dead entries!\n", dev->name);
-                nv_drain_tx(dev);
-                nv_init_tx(dev);
-                setup_hw_rings(dev, NV_SETUP_TX_RING);
-        }
+        /* save current HW postion */
+        if (np->tx_change_owner)
+                put_tx.ex = np->tx_change_owner->first_tx_desc;
+        else
+                put_tx = np->put_tx;
 
-        netif_wake_queue(dev);
+        /* 3) clear all tx state */
+        nv_drain_tx(dev);
+        nv_init_tx(dev);
+
+        /* 4) restore state to current HW position */
+        np->get_tx = np->put_tx = put_tx;
+        np->tx_limit = saved_tx_limit;
 
-        /* 4) restart tx engine */
+        /* 5) restart tx engine */
         nv_start_tx(dev);
+        netif_wake_queue(dev);
         spin_unlock_irq(&np->lock);
 }