drivers/net: fixed drivers that support netpoll use ndo_start_xmit()
The NETPOLL API requires that interrupts remain disabled in
netpoll_send_skb(). The use of "A functions set" in the NETPOLL API
callbacks causes the interrupts to get enabled and can lead to kernel
instability.
The solution is to use "B functions set" to prevent the irqs from
getting enabled while in netpoll_send_skb().
A functions set:
local_irq_disable()/local_irq_enable()
spin_lock_irq()/spin_unlock_irq()
spin_trylock_irq()/spin_unlock_irq()
B functions set:
local_irq_save()/local_irq_restore()
spin_lock_irqsave()/spin_unlock_irqrestore()
spin_trylock_irqsave()/spin_unlock_irqrestore()
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/mlx4/en_tx.c b/drivers/net/mlx4/en_tx.c
index 5a88b3f5..6220840 100644
--- a/drivers/net/mlx4/en_tx.c
+++ b/drivers/net/mlx4/en_tx.c
@@ -437,6 +437,7 @@
{
struct mlx4_en_cq *cq = &priv->tx_cq[tx_ind];
struct mlx4_en_tx_ring *ring = &priv->tx_ring[tx_ind];
+ unsigned long flags;
/* If we don't have a pending timer, set one up to catch our recent
post in case the interface becomes idle */
@@ -445,9 +446,9 @@
/* Poll the CQ every mlx4_en_TX_MODER_POLL packets */
if ((++ring->poll_cnt & (MLX4_EN_TX_POLL_MODER - 1)) == 0)
- if (spin_trylock_irq(&ring->comp_lock)) {
+ if (spin_trylock_irqsave(&ring->comp_lock, flags)) {
mlx4_en_process_tx_cq(priv->dev, cq);
- spin_unlock_irq(&ring->comp_lock);
+ spin_unlock_irqrestore(&ring->comp_lock, flags);
}
}