Commit 465440d2 authored by Yevgeny Petrilin's avatar Yevgeny Petrilin Committed by David S. Miller
Browse files

mlx4_en: Fix a kernel panic when waking tx queue 



When the transmit queue gets full we enable interrupts for TX completions
There was a race that we handled the TX queue both from the interrupt context
and from the transmit function. Using "spin_trylock_irq()" ensures this
doesn't happen.

Signed-off-by: default avatarYevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e8573758

drivers/net/mlx4/en_tx.c

+4 −4
Original line number Diff line number Diff line
@@ -426,7 +426,7 @@ void mlx4_en_poll_tx_cq(unsigned long data) 


	INC_PERF_COUNTER(priv->pstats.tx_poll);



	if (!spin_trylock(&ring->comp_lock)) {

	if (!spin_trylock_irq(&ring->comp_lock)) {

		mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT);

		return;

	}
@@ -439,7 +439,7 @@ void mlx4_en_poll_tx_cq(unsigned long data) 
	if (inflight && priv->port_up)

		mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT);



	spin_unlock(&ring->comp_lock);

	spin_unlock_irq(&ring->comp_lock);

}



static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv,
@@ -482,9 +482,9 @@ static inline void mlx4_en_xmit_poll(struct mlx4_en_priv *priv, int tx_ind) 


	/* Poll the CQ every mlx4_en_TX_MODER_POLL packets */

	if ((++ring->poll_cnt & (MLX4_EN_TX_POLL_MODER - 1)) == 0)

		if (spin_trylock(&ring->comp_lock)) {

		if (spin_trylock_irq(&ring->comp_lock)) {

			mlx4_en_process_tx_cq(priv->dev, cq);

			spin_unlock(&ring->comp_lock);

			spin_unlock_irq(&ring->comp_lock);

		}

}

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