[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: Dale Farnsworth <dale@farnsworth.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index 40ae36b..9eeb8db 100644 (file)
--- a/drivers/net/mv643xx_eth.c
+++ b/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