ATHEROS-ALX: Use dma_set_mask_and_coherent and fix a bug

1. For the 64 bits dma mask use dma_set_mask_and_coherent instead of
   dma_set_mask and dma_set_coherent_mask.

2. For the 32 bits dma mask dma_set_coherent_mask is only called if
   dma_set_mask fails, which is unusual. Assuming this as a bug, fixes
   it by replacing calls to dma_set_mask and dma_set_coherent_mask by a
   call to dma_set_mask_and_coherent.

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Tested-by: Jonas Hahnfeld <hahnjo@hahnjo.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/atheros/alx/main.c

@@ -1248,19 +1248,13 @@ static int alx_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	 * shared register for the high 32 bits, so only a single, aligned,
 	 * 4 GB physical address range can be used for descriptors.
 	 */
-	if (!dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)) &&
-	    !dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64))) {
+	if (!dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64))) {
 		dev_dbg(&pdev->dev, "DMA to 64-BIT addresses\n");
 	} else {
-		err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
+		err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 		if (err) {
-			err = dma_set_coherent_mask(&pdev->dev,
-						    DMA_BIT_MASK(32));
-			if (err) {
-				dev_err(&pdev->dev,
-					"No usable DMA config, aborting\n");
-				goto out_pci_disable;
-			}
+			dev_err(&pdev->dev, "No usable DMA config, aborting\n");
+			goto out_pci_disable;
 		}
 	}