DMA-API: parport: parport_pc.c: use dma_coerce_mask_and_coherent()

The code sequence:
	dev->coherent_dma_mask = DMA_BIT_MASK(24);
	dev->dma_mask = &dev->coherent_dma_mask;
bypasses the architectures check on the DMA mask.  It can be replaced
with dma_coerce_mask_and_coherent(), avoiding the direct initialization
of this mask.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/parport/parport_pc.c

@@ -2004,6 +2004,7 @@ struct parport *parport_pc_probe_port(unsigned long int base,
 	struct resource	*ECR_res = NULL;
 	struct resource	*EPP_res = NULL;
 	struct platform_device *pdev = NULL;
+	int ret;
 
 	if (!dev) {
 		/* We need a physical device to attach to, but none was
@@ -2014,8 +2015,11 @@ struct parport *parport_pc_probe_port(unsigned long int base,
 			return NULL;
 		dev = &pdev->dev;
 
-		dev->coherent_dma_mask = DMA_BIT_MASK(24);
-		dev->dma_mask = &dev->coherent_dma_mask;
+		ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(24));
+		if (ret) {
+			dev_err(dev, "Unable to set coherent dma mask: disabling DMA\n");
+			dma = PARPORT_DMA_NONE;
+		}
 	}
 
 	ops = kmalloc(sizeof(struct parport_operations), GFP_KERNEL);