Subject: [PATCH v2 2/3] libahci: Implement the capability to override the generic ahci interrupt handler.

From: [email-masked] (Suman Tripathi)
Date: Wed, 27 Jan 2016 15:19:56 +0530

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

Signed-off-by: Suman Tripathi <[email-masked]>
---
 drivers/ata/ahci.h    |    2 ++
 drivers/ata/libahci.c |   13 ++++++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index e9b57e8..284ce3a 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -359,6 +359,7 @@ 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
@@ -422,6 +423,7 @@ 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 08be136..fa098c6 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_level_irq_intr(int irq, void *dev_instance)
 {
@@ -2466,13 +2467,19 @@ 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;
+	irqreturn_t (*ahci_irq_handler)(int irq, void *dev_instance);
 	int rc;

 	if (hpriv->flags & (AHCI_HFLAG_MULTI_MSI | AHCI_HFLAG_MULTI_MSIX))
 		rc = ahci_host_activate_multi_irqs(host, sht);
-	else
-		rc = ata_host_activate(host, irq, ahci_single_level_irq_intr,
+	else {
+		ahci_irq_handler = hpriv->ahci_irq_intr ? hpriv->ahci_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