staging: comedi: adl_pci9118: DMA requires an interrupt

In order for DMA to work we also need an interrupt. Refactor the code
so that the DMA allocation is only done if the interrupt is available.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/adl_pci9118.c

@@ -1775,8 +1775,16 @@ static int pci9118_common_attach(struct comedi_device *dev, int disable_irq,
 
 	pci9118_reset(dev);
 
-	if (master)
-		pci9118_alloc_dma(dev);
+	if (!disable_irq && pcidev->irq) {
+		ret = request_irq(pcidev->irq, pci9118_interrupt, IRQF_SHARED,
+				  dev->board_name, dev);
+		if (ret == 0) {
+			dev->irq = pcidev->irq;
+
+			if (master)
+				pci9118_alloc_dma(dev);
+		}
+	}
 
 	if (ext_mux > 0) {
 		if (ext_mux > 256)
@@ -1804,13 +1812,6 @@ static int pci9118_common_attach(struct comedi_device *dev, int disable_irq,
 	pci_write_config_word(pcidev, PCI_COMMAND, u16w | 64);
 				/* Enable parity check for parity error */
 
-	if (!disable_irq && pcidev->irq) {
-		ret = request_irq(pcidev->irq, pci9118_interrupt, IRQF_SHARED,
-				  dev->board_name, dev);
-		if (ret == 0)
-			dev->irq = pcidev->irq;
-	}
-
 	ret = comedi_alloc_subdevices(dev, 4);
 	if (ret)
 		return ret;