[PATCH] mv643xx_eth: Fix spinlock recursion bug

This patch eliminates a spinlock recursion bug introduced recently.
Since eth_port_send() is always called with the lock held, we simply
remove the locking inside the function itself.
Signed-off-by: NDale Farnsworth <dale@farnsworth.org>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

drivers/net/mv643xx_eth.c

@@ -2617,7 +2617,6 @@ static ETH_FUNC_RET_STATUS eth_port_send(struct mv643xx_private *mp,
 	struct eth_tx_desc *current_descriptor;
 	struct eth_tx_desc *first_descriptor;
 	u32 command;
-	unsigned long flags;
 
 	/* Do not process Tx ring in case of Tx ring resource error */
 	if (mp->tx_resource_err)
@@ -2634,8 +2633,6 @@ static ETH_FUNC_RET_STATUS eth_port_send(struct mv643xx_private *mp,
 		return ETH_ERROR;
 	}
 
-	spin_lock_irqsave(&mp->lock, flags);
-
 	mp->tx_ring_skbs++;
 	BUG_ON(mp->tx_ring_skbs > mp->tx_ring_size);
 
@@ -2685,15 +2682,11 @@ static ETH_FUNC_RET_STATUS eth_port_send(struct mv643xx_private *mp,
 		mp->tx_resource_err = 1;
 		mp->tx_curr_desc_q = tx_first_desc;
 
-		spin_unlock_irqrestore(&mp->lock, flags);
-
 		return ETH_QUEUE_LAST_RESOURCE;
 	}
 
 	mp->tx_curr_desc_q = tx_next_desc;
 
-	spin_unlock_irqrestore(&mp->lock, flags);
-
 	return ETH_OK;
 }
 #else
@@ -2704,14 +2697,11 @@ static ETH_FUNC_RET_STATUS eth_port_send(struct mv643xx_private *mp,
 	int tx_desc_used;
 	struct eth_tx_desc *current_descriptor;
 	unsigned int command_status;
-	unsigned long flags;
 
 	/* Do not process Tx ring in case of Tx ring resource error */
 	if (mp->tx_resource_err)
 		return ETH_QUEUE_FULL;
 
-	spin_lock_irqsave(&mp->lock, flags);
-
 	mp->tx_ring_skbs++;
 	BUG_ON(mp->tx_ring_skbs > mp->tx_ring_size);
 
@@ -2742,12 +2732,9 @@ static ETH_FUNC_RET_STATUS eth_port_send(struct mv643xx_private *mp,
 	/* Check for ring index overlap in the Tx desc ring */
 	if (tx_desc_curr == tx_desc_used) {
 		mp->tx_resource_err = 1;
-
-		spin_unlock_irqrestore(&mp->lock, flags);
 		return ETH_QUEUE_LAST_RESOURCE;
 	}
 
-	spin_unlock_irqrestore(&mp->lock, flags);
 	return ETH_OK;
 }
 #endif