ata: Remove the AHCI_HFLAG_EDGE_IRQ support from libahci.

The flexibility to override the irq handles in the LLD's are already
present, so controllers implementing a edge trigger latch can
implement their own interrupt handler inside the driver.  This patch
removes the AHCI_HFLAG_EDGE_IRQ support from libahci and moves edge
irq handling to ahci_xgene.

tj: Minor update to description.

Signed-off-by: Suman Tripathi <stripathi@apm.com>
Signed-off-by: Tejun Heo <tj@kenrel.org>

drivers/ata/ahci.h

@@ -240,8 +240,7 @@ enum {
 						        error-handling stage) */
 	AHCI_HFLAG_NO_DEVSLP		= (1 << 17), /* no device sleep */
 	AHCI_HFLAG_NO_FBS		= (1 << 18), /* no FBS */
-	AHCI_HFLAG_EDGE_IRQ		= (1 << 19), /* HOST_IRQ_STAT behaves as
-							Edge Triggered */
+
 #ifdef CONFIG_PCI_MSI
 	AHCI_HFLAG_MULTI_MSI		= (1 << 20), /* multiple PCI MSIs */
 	AHCI_HFLAG_MULTI_MSIX		= (1 << 21), /* per-port MSI-X */

drivers/ata/ahci_xgene.c

@@ -548,6 +548,43 @@ static int xgene_ahci_softreset(struct ata_link *link, unsigned int *class,
 	return rc;
 }
 
+static irqreturn_t xgene_ahci_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);
+
+	/*
+	 * HOST_IRQ_STAT behaves as edge triggered latch meaning that
+	 * it should be cleared before all the port events are cleared.
+	 */
+	writel(irq_stat, mmio + HOST_IRQ_STAT);
+
+	rc = ahci_handle_port_intr(host, irq_masked);
+
+	spin_unlock(&host->lock);
+
+	VPRINTK("EXIT\n");
+
+	return IRQ_RETVAL(rc);
+}
+
 static struct ata_port_operations xgene_ahci_v1_ops = {
 	.inherits = &ahci_ops,
 	.host_stop = xgene_ahci_host_stop,
@@ -779,7 +816,8 @@ static int xgene_ahci_probe(struct platform_device *pdev)
 		hpriv->flags = AHCI_HFLAG_NO_NCQ;
 		break;
 	case XGENE_AHCI_V2:
-		hpriv->flags |= AHCI_HFLAG_YES_FBS | AHCI_HFLAG_EDGE_IRQ;
+		hpriv->flags |= AHCI_HFLAG_YES_FBS;
+		hpriv->irq_handler = xgene_ahci_irq_intr;
 		break;
 	default:
 		break;

drivers/ata/libahci.c

@@ -113,8 +113,6 @@ static ssize_t ahci_store_em_buffer(struct device *dev,
 				    const char *buf, size_t size);
 static ssize_t ahci_show_em_supported(struct device *dev,
 				      struct device_attribute *attr, char *buf);
-static irqreturn_t ahci_single_edge_irq_intr(int irq, void *dev_instance);
-
 static irqreturn_t ahci_single_level_irq_intr(int irq, void *dev_instance);
 
 static DEVICE_ATTR(ahci_host_caps, S_IRUGO, ahci_show_host_caps, NULL);
@@ -517,9 +515,7 @@ void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv)
 		hpriv->start_engine = ahci_start_engine;
 
 	if (!hpriv->irq_handler)
-		hpriv->irq_handler = (hpriv->flags & AHCI_HFLAG_EDGE_IRQ) ?
-				     ahci_single_edge_irq_intr :
-				     ahci_single_level_irq_intr;
+		hpriv->irq_handler = ahci_single_level_irq_intr;
 }
 EXPORT_SYMBOL_GPL(ahci_save_initial_config);
 
@@ -1882,43 +1878,6 @@ u32 ahci_handle_port_intr(struct ata_host *host, u32 irq_masked)
 }
 EXPORT_SYMBOL_GPL(ahci_handle_port_intr);
 
-static irqreturn_t ahci_single_edge_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);
-
-	/*
-	 * HOST_IRQ_STAT behaves as edge triggered latch meaning that
-	 * it should be cleared before all the port events are cleared.
-	 */
-	writel(irq_stat, mmio + HOST_IRQ_STAT);
-
-	rc = ahci_handle_port_intr(host, irq_masked);
-
-	spin_unlock(&host->lock);
-
-	VPRINTK("EXIT\n");
-
-	return IRQ_RETVAL(rc);
-}
-
 static irqreturn_t ahci_single_level_irq_intr(int irq, void *dev_instance)
 {
 	struct ata_host *host = dev_instance;