pata_isapnp: Polled devices

If a card has no IRQ then pass no interrupt handler but allow polled
usage.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/ata/pata_isapnp.c

@@ -75,13 +75,16 @@ static int isapnp_init_one(struct pnp_dev *idev, const struct pnp_device_id *dev
 	struct ata_host *host;
 	struct ata_port *ap;
 	void __iomem *cmd_addr, *ctl_addr;
+	int irq = 0;
+	irq_handler_t handler = NULL;
 
 	if (pnp_port_valid(idev, 0) == 0)
 		return -ENODEV;
 
-	/* FIXME: Should selected polled PIO here not fail */
-	if (pnp_irq_valid(idev, 0) == 0)
-		return -ENODEV;
+	if (pnp_irq_valid(idev, 0)) {
+		irq = pnp_irq(idev, 0);
+		handler = ata_interrupt;
+	}
 
 	/* allocate host */
 	host = ata_host_alloc(&idev->dev, 1);
@@ -115,7 +118,7 @@ static int isapnp_init_one(struct pnp_dev *idev, const struct pnp_device_id *dev
 		      (unsigned long long)pnp_port_start(idev, 1));
 
 	/* activate */
-	return ata_host_activate(host, pnp_irq(idev, 0), ata_interrupt, 0,
+	return ata_host_activate(host, irq, handler, 0,
 				 &isapnp_sht);
 }