net: ethernet: wiznet: Remove create_workqueue

alloc_workqueue replaces deprecated create_workqueue().

A dedicated workqueue has been used since the workitems are involved
in normal device operation. Workitems &priv->rx_work and &priv->tx_work,
map to w5100_rx_work and w5100_tx_work respectively and are involved in
receiving and transmitting packets. Forward progress under
memory pressure is a requirement here.

create_workqueue has been replaced with alloc_workqueue with max_active
as 0 since there is no need for throttling the number of active work
items.

Since the driver may be used in memory reclaim path,
WQ_MEM_RECLAIM has been set to guarantee forward progress.

flush_workqueue is unnecessary since destroy_workqueue() itself calls
drain_workqueue() which flushes repeatedly till the workqueue
becomes empty. Hence the call to flush_workqueue() has been dropped.

Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/wiznet/w5100.c

@@ -1154,7 +1154,7 @@ int w5100_probe(struct device *dev, const struct w5100_ops *ops,
 	if (err < 0)
 		goto err_register;
 
-	priv->xfer_wq = create_workqueue(netdev_name(ndev));
+	priv->xfer_wq = alloc_workqueue(netdev_name(ndev), WQ_MEM_RECLAIM, 0);
 	if (!priv->xfer_wq) {
 		err = -ENOMEM;
 		goto err_wq;
@@ -1233,7 +1233,6 @@ int w5100_remove(struct device *dev)
 
 	flush_work(&priv->setrx_work);
 	flush_work(&priv->restart_work);
-	flush_workqueue(priv->xfer_wq);
 	destroy_workqueue(priv->xfer_wq);
 
 	unregister_netdev(ndev);