releases/3.14.5/mlx4_en-don-t-use-napi_synchronize-inside-mlx4_en_netpoll.patch

From c98235cb8584a72e95786e17d695a8e5fafcd766 Mon Sep 17 00:00:00 2001
From: Chris Mason <clm@fb.com>
Date: Tue, 15 Apr 2014 18:09:24 -0400
Subject: mlx4_en: don't use napi_synchronize inside mlx4_en_netpoll

From: Chris Mason <clm@fb.com>

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/net/ethernet/mellanox/mlx4/en_cq.c     |    1 -
 drivers/net/ethernet/mellanox/mlx4/en_netdev.c |    6 +-----
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h   |    1 -
 3 files changed, 1 insertion(+), 7 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx4/en_cq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
@@ -66,7 +66,6 @@ int mlx4_en_create_cq(struct mlx4_en_pri
 
 	cq->ring = ring;
 	cq->is_tx = mode;
-	spin_lock_init(&cq->lock);
 
 	/* Allocate HW buffers on provided NUMA node.
 	 * dev->numa_node is used in mtt range allocation flow.
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -1315,15 +1315,11 @@ static void mlx4_en_netpoll(struct net_d
 {
 	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
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -309,7 +309,6 @@ 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;
 	int size;