net: ethernet: ixp4xx: Set the DMA masks explicitly

The former fix only papered over the actual problem: the
ethernet core expects the netdev .dev member to have the
proper DMA masks set, or there will be BUG_ON() triggered
in kernel/dma/mapping.c.

Fix this by simply copying dma_mask and dma_mask_coherent
from the parent device.

Fixes: e45d0fa ("net: ethernet: ixp4xx: Use parent dev for DMA pool")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: Linus Walleij

drivers/net/ethernet/xscale/ixp4xx_eth.c

@@ -1085,7 +1085,7 @@ static int init_queues(struct port *port)
 	int i;
 
 	if (!ports_open) {
-		dma_pool = dma_pool_create(DRV_NAME, port->netdev->dev.parent,
+		dma_pool = dma_pool_create(DRV_NAME, &port->netdev->dev,
 					   POOL_ALLOC_SIZE, 32, 0);
 		if (!dma_pool)
 			return -ENOMEM;
@@ -1435,6 +1435,9 @@ static int ixp4xx_eth_probe(struct platform_device *pdev)
 	ndev->netdev_ops = &ixp4xx_netdev_ops;
 	ndev->ethtool_ops = &ixp4xx_ethtool_ops;
 	ndev->tx_queue_len = 100;
+	/* Inherit the DMA masks from the platform device */
+	ndev->dev.dma_mask = dev->dma_mask;
+	ndev->dev.coherent_dma_mask = dev->coherent_dma_mask;
 
 	netif_napi_add(ndev, &port->napi, eth_poll, NAPI_WEIGHT);