From d8498088cf466483093c9a29121e3833e7923287 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Thu, 5 Jun 2014 10:22:15 -0700 Subject: [PATCH] net: systemport: fix transmit locking scheme Our transmit locking scheme did not account for the TX ring full interrupt. If a TX ring full interrupt fires while we are attempting to transmit, we will cause a deadlock to occur. Fix this by making sure that we properly disable interrupts while acquiring the spinlock. Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/bcmsysport.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c index 25982b02f0ea..4dfc93fe9744 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -637,10 +637,11 @@ static unsigned int bcm_sysport_tx_reclaim(struct bcm_sysport_priv *priv, struct bcm_sysport_tx_ring *ring) { unsigned int released; + unsigned long flags; - spin_lock(&ring->lock); + spin_lock_irqsave(&ring->lock, flags); released = __bcm_sysport_tx_reclaim(priv, ring); - spin_unlock(&ring->lock); + spin_unlock_irqrestore(&ring->lock, flags); return released; } @@ -822,6 +823,7 @@ static netdev_tx_t bcm_sysport_xmit(struct sk_buff *skb, struct netdev_queue *txq; struct dma_desc *desc; unsigned int skb_len; + unsigned long flags; dma_addr_t mapping; u32 len_status; u16 queue; @@ -831,8 +833,8 @@ static netdev_tx_t bcm_sysport_xmit(struct sk_buff *skb, txq = netdev_get_tx_queue(dev, queue); ring = &priv->tx_rings[queue]; - /* lock against tx reclaim in BH context */ - spin_lock(&ring->lock); + /* lock against tx reclaim in BH context and TX ring full interrupt */ + spin_lock_irqsave(&ring->lock, flags); if (unlikely(ring->desc_count == 0)) { netif_tx_stop_queue(txq); netdev_err(dev, "queue %d awake and ring full!\n", queue); @@ -914,7 +916,7 @@ static netdev_tx_t bcm_sysport_xmit(struct sk_buff *skb, ret = NETDEV_TX_OK; out: - spin_unlock(&ring->lock); + spin_unlock_irqrestore(&ring->lock, flags); return ret; } -- 2.20.1