commit 8f24664da64f8db094cd9d379b16fc1d8776d1df
author Stephen Hemminger <shemminger@osdl.org> Mon Mar 20 15:48:21 2006 -0800
committer Jeff Garzik <jeff@garzik.org> Tue Mar 21 16:00:52 2006 -0500
tree c954d1ac501e3f4f4c5473cdc96bf46894b129d9
parent d89e1343959200a578465d50bb36c89733cf66a7

[PATCH] sky2: transmit recovery

This patch decodes state and revovers from any races in the transmit
timeout and NAPI logic. It should never trigger, but if it does then
do the right thing.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/net/sky2.c

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index ffe3aa7..ab36a74 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -1328,7 +1328,7 @@
 	}
 
 	sky2->tx_cons = put;
-	if (netif_queue_stopped(dev) && tx_avail(sky2) > MAX_SKB_TX_LE)
+	if (tx_avail(sky2) > MAX_SKB_TX_LE)
 		netif_wake_queue(dev);
 }
 
@@ -1651,17 +1651,40 @@
 	struct sky2_port *sky2 = netdev_priv(dev);
 	struct sky2_hw *hw = sky2->hw;
 	unsigned txq = txqaddr[sky2->port];
+	u16 report, done;
 
 	if (netif_msg_timer(sky2))
 		printk(KERN_ERR PFX "%s: tx timeout\n", dev->name);
 
-	sky2_write32(hw, Q_ADDR(txq, Q_CSR), BMU_STOP);
-	sky2_write32(hw, Y2_QADDR(txq, PREF_UNIT_CTRL), PREF_UNIT_RST_SET);
+	report = sky2_read16(hw, sky2->port == 0 ? STAT_TXA1_RIDX : STAT_TXA2_RIDX);
+	done = sky2_read16(hw, Q_ADDR(txq, Q_DONE));
 
-	sky2_tx_clean(sky2);
+	printk(KERN_DEBUG PFX "%s: transmit ring %u .. %u report=%u done=%u\n",
+	       dev->name,
+	       sky2->tx_cons, sky2->tx_prod, report, done);
 
-	sky2_qset(hw, txq);
-	sky2_prefetch_init(hw, txq, sky2->tx_le_map, TX_RING_SIZE - 1);
+	if (report != done) {
+		printk(KERN_INFO PFX "status burst pending (irq moderation?)\n");
+
+		sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_STOP);
+		sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_START);
+	} else if (report != sky2->tx_cons) {
+		printk(KERN_INFO PFX "status report lost?\n");
+
+		spin_lock_bh(&sky2->tx_lock);
+		sky2_tx_complete(sky2, report);
+		spin_unlock_bh(&sky2->tx_lock);
+	} else {
+		printk(KERN_INFO PFX "hardware hung? flushing\n");
+
+		sky2_write32(hw, Q_ADDR(txq, Q_CSR), BMU_STOP);
+		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);
+	}
 }
 
 
@@ -2097,6 +2120,8 @@
 	prefetch(&hw->st_le[hw->st_idx]);
 	if (likely(__netif_rx_schedule_prep(dev0)))
 		__netif_rx_schedule(dev0);
+	else
+		printk(KERN_DEBUG PFX "irq race detected\n");
 
 	return IRQ_HANDLED;
 }