libahci: Refactoring of ahci_single_irq_intr function.

This patch refactors the ahci_single_irq_intr function and also rename
it to ahci_single_level_irq_intr as it handles a level triggered latch.
Signed-off-by: Suman tripathi <stripathi@apm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/ata/libahci.c

@@ -1826,27 +1826,9 @@ static irqreturn_t ahci_multi_irqs_intr(int irq, void *dev_instance)
 	return IRQ_WAKE_THREAD;
 }
 
-static irqreturn_t ahci_single_irq_intr(int irq, void *dev_instance)
+static u32 ahci_handle_port_intr(struct ata_host *host, u32 irq_masked)
 {
-	struct ata_host *host = dev_instance;
-	struct ahci_host_priv *hpriv;
 	unsigned int i, handled = 0;
-	void __iomem *mmio;
-	u32 irq_stat, irq_masked;
-
-	VPRINTK("ENTER\n");
-
-	hpriv = host->private_data;
-	mmio = hpriv->mmio;
-
-	/* sigh.  0xffffffff is a valid return from h/w */
-	irq_stat = readl(mmio + HOST_IRQ_STAT);
-	if (!irq_stat)
-		return IRQ_NONE;
-
-	irq_masked = irq_stat & hpriv->port_map;
-
-	spin_lock(&host->lock);
 
 	for (i = 0; i < host->n_ports; i++) {
 		struct ata_port *ap;
@@ -1868,6 +1850,33 @@ static irqreturn_t ahci_single_irq_intr(int irq, void *dev_instance)
 		handled = 1;
 	}
 
+	return handled;
+}
+
+static irqreturn_t ahci_single_level_irq_intr(int irq, void *dev_instance)
+{
+	struct ata_host *host = dev_instance;
+	struct ahci_host_priv *hpriv;
+	unsigned int rc = 0;
+	void __iomem *mmio;
+	u32 irq_stat, irq_masked;
+
+	VPRINTK("ENTER\n");
+
+	hpriv = host->private_data;
+	mmio = hpriv->mmio;
+
+	/* sigh.  0xffffffff is a valid return from h/w */
+	irq_stat = readl(mmio + HOST_IRQ_STAT);
+	if (!irq_stat)
+		return IRQ_NONE;
+
+	irq_masked = irq_stat & hpriv->port_map;
+
+	spin_lock(&host->lock);
+
+	rc = ahci_handle_port_intr(host, irq_masked);
+
 	/* HOST_IRQ_STAT behaves as level triggered latch meaning that
 	 * it should be cleared after all the port events are cleared;
 	 * otherwise, it will raise a spurious interrupt after each
@@ -1883,7 +1892,7 @@ static irqreturn_t ahci_single_irq_intr(int irq, void *dev_instance)
 
 	VPRINTK("EXIT\n");
 
-	return IRQ_RETVAL(handled);
+	return IRQ_RETVAL(rc);
 }
 
 unsigned int ahci_qc_issue(struct ata_queued_cmd *qc)
@@ -2487,7 +2496,7 @@ int ahci_host_activate(struct ata_host *host, int irq,
 	if (hpriv->flags & AHCI_HFLAG_MULTI_MSI)
 		rc = ahci_host_activate_multi_irqs(host, irq, sht);
 	else
-		rc = ata_host_activate(host, irq, ahci_single_irq_intr,
+		rc = ata_host_activate(host, irq, ahci_single_level_irq_intr,
 				       IRQF_SHARED, sht);
 	return rc;
 }