mlx4_en: don't use napi_synchronize inside mlx4_en_netpoll

commit c98235cb8584a72e95786e17d695a8e5fafcd766 upstream.

The mlx4 driver is triggering schedules while atomic inside
mlx4_en_netpoll:

	spin_lock_irqsave(&cq->lock, flags);
	napi_synchronize(&cq->napi);
		^^^^^ msleep here
	mlx4_en_process_rx_cq(dev, cq, 0);
	spin_unlock_irqrestore(&cq->lock, flags);

This was part of a patch by Alexander Guller from Mellanox in 2011,
but it still isn't upstream.

Signed-off-by: Chris Mason <clm@fb.com>
Acked-By: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_cq.c b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
index 5829e0b47e7e5963a8d5913505f2c3f5392dfbab..ba7c861e2b9344568eee59873a6fa70973444308 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/en_cq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
@@ -58,7 +58,6 @@ int mlx4_en_create_cq(struct mlx4_en_priv *priv,
 
        cq->ring = ring;
        cq->is_tx = mode;
-       spin_lock_init(&cq->lock);
 
        err = mlx4_alloc_hwq_res(mdev->dev, &cq->wqres,
                                cq->buf_size, 2 * PAGE_SIZE);

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index 78d776bc355c747d37fafa77a90117daead68ec3..308349a43d60c0e3df35033990f3fa8dd82875d5 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -355,15 +355,11 @@ static void mlx4_en_netpoll(struct net_device *dev)
 {
        struct mlx4_en_priv *priv = netdev_priv(dev);
        struct mlx4_en_cq *cq;
-       unsigned long flags;
        int i;
 
        for (i = 0; i < priv->rx_ring_num; i++) {
                cq = &priv->rx_cq[i];
-               spin_lock_irqsave(&cq->lock, flags);
-               napi_synchronize(&cq->napi);
-               mlx4_en_process_rx_cq(dev, cq, 0);
-               spin_unlock_irqrestore(&cq->lock, flags);
+               napi_schedule(&cq->napi);
        }
 }
 #endif

diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 207b5add3ca848134ea44bf3fadd918ef2912c3f..492055885109e6a727102708eb456ea48f97c7ad 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -300,7 +300,6 @@ struct mlx4_en_cq {
        struct mlx4_cq          mcq;
        struct mlx4_hwq_resources wqres;
        int                     ring;
-       spinlock_t              lock;
        struct net_device      *dev;
        struct napi_struct      napi;
        /* Per-core Tx cq processing support */