[PATCH v3 1/3] libahci: Implement the capability to override the generic ahci interrupt handler.

[suman Tripathi <stripathi@apm.com>]

From: Suman Tripathi <stripathi@apm.com>

This patch implements the capability to override the generic
ahci interrupt handler so that the LDD drivers can implement
there own custom interrupt handler routines.

Signed-off-by: Suman Tripathi <stripathi@apm.com>
---
 drivers/ata/ahci.h    |    2 ++
 drivers/ata/libahci.c |   32 +++++++++++++++++++++++---------
 2 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index a4faa43..3d883ee 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -360,6 +360,7 @@ struct ahci_host_priv {
 	 * be overridden anytime before the host is activated.
 	 */
 	void			(*start_engine)(struct ata_port *ap);
+	irqreturn_t 		(*ahci_irq_intr)(int irq, void *dev_instance);
 };

 #ifdef CONFIG_PCI_MSI
@@ -423,6 +424,7 @@ int ahci_reset_em(struct ata_host *host);
 void ahci_print_info(struct ata_host *host, const char *scc_s);
 int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht);
 void ahci_error_handler(struct ata_port *ap);
+u32 ahci_handle_port_intr(struct ata_host *host, u32 irq_masked);

 static inline void __iomem *__ahci_port_base(struct ata_host *host,
 					     unsigned int port_no)
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index eda3cf2..5d3035a 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1816,7 +1816,7 @@ static irqreturn_t ahci_multi_irqs_intr_hard(int irq, void *dev_instance)
 	return IRQ_HANDLED;
 }

-static u32 ahci_handle_port_intr(struct ata_host *host, u32 irq_masked)
+u32 ahci_handle_port_intr(struct ata_host *host, u32 irq_masked)
 {
 	unsigned int i, handled = 0;

@@ -1842,6 +1842,7 @@ static u32 ahci_handle_port_intr(struct ata_host *host, u32 irq_masked)

 	return handled;
 }
+EXPORT_SYMBOL_GPL(ahci_handle_port_intr);

 static irqreturn_t ahci_single_edge_irq_intr(int irq, void *dev_instance)
 {
@@ -2504,15 +2505,28 @@ int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht)
 	struct ahci_host_priv *hpriv = host->private_data;
 	int irq = hpriv->irq;
 	int rc;
+	irqreturn_t (*ahci_irq_handler)(int irq, void *dev_instance);

-	if (hpriv->flags & (AHCI_HFLAG_MULTI_MSI | AHCI_HFLAG_MULTI_MSIX))
-		rc = ahci_host_activate_multi_irqs(host, sht);
-	else if (hpriv->flags & AHCI_HFLAG_EDGE_IRQ)
-		rc = ata_host_activate(host, irq, ahci_single_edge_irq_intr,
-				       IRQF_SHARED, sht);
-	else
-		rc = ata_host_activate(host, irq, ahci_single_level_irq_intr,
-				       IRQF_SHARED, sht);
+	ahci_irq_handler = hpriv->ahci_irq_intr;
+
+	if (hpriv->flags & (AHCI_HFLAG_MULTI_MSI | AHCI_HFLAG_MULTI_MSIX)) {
+		if (!ahci_irq_handler)
+			rc = ahci_host_activate_multi_irqs(host, sht);
+		else
+			dev_warn(host->dev, "both AHCI_HFLAG_MULTI_MSI flag set \
+				 and custom irq handler implemented\n");
+
+	} else {
+		if (!ahci_irq_handler) {
+			ahci_irq_handler = (hpriv->flags & AHCI_HFLAG_EDGE_IRQ ?
+			 		    ahci_single_edge_irq_intr :
+					    ahci_single_level_irq_intr);
+		}
+	}
+
+	rc = ata_host_activate(host, irq, ahci_irq_handler,
+			       IRQF_SHARED, sht);
+
 	return rc;
 }
 EXPORT_SYMBOL_GPL(ahci_host_activate);
--
1.7.1