ethernet: s2io: don't call dev_kfree_skb() under spin_lock_irqsave()

BugLink: https://bugs.launchpad.net/bugs/2003914

[ Upstream commit 6cee96e ]

It is not allowed to call kfree_skb() or consume_skb() from hardware
interrupt context or with hardware interrupts being disabled.

It should use dev_kfree_skb_irq() or dev_consume_skb_irq() instead.
The difference between them is free reason, dev_kfree_skb_irq() means
the SKB is dropped in error and dev_consume_skb_irq() means the SKB
is consumed in normal.

In this case, dev_kfree_skb() is called in free_tx_buffers() to drop
the SKBs in tx buffers, when the card is down, so replace it with
dev_kfree_skb_irq() here.

Fixes: 1da177e ("Linux-2.6.12-rc2")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

Author: Yang Yingliang

drivers/net/ethernet/neterion/s2io.c

@@ -2375,7 +2375,7 @@ static void free_tx_buffers(struct s2io_nic *nic)
 			skb = s2io_txdl_getskb(&mac_control->fifos[i], txdp, j);
 			if (skb) {
 				swstats->mem_freed += skb->truesize;
-				dev_kfree_skb(skb);
+				dev_kfree_skb_irq(skb);
 				cnt++;
 			}
 		}