ahci: Store interrupt value

Use a stored value for which interrupts to enable.  Changing this allows
us to selectively turn off certain interrupts later and have them
stay off.

Signed-off-by:  Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index d52b73a..baf7d05 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -175,6 +175,7 @@
 	AHCI_FLAG_32BIT_ONLY		= (1 << 28), /* force 32bit */
 	AHCI_FLAG_MV_PATA		= (1 << 29), /* PATA port */
 	AHCI_FLAG_NO_MSI		= (1 << 30), /* no PCI MSI */
+	AHCI_FLAG_NO_HOTPLUG		= (1 << 31), /* ignore PxSERR.DIAG.N */
 
 	AHCI_FLAG_COMMON		= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
 					  ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA |
@@ -215,6 +216,7 @@
 	unsigned int		ncq_saw_d2h:1;
 	unsigned int		ncq_saw_dmas:1;
 	unsigned int		ncq_saw_sdb:1;
+	u32 			intr_mask;	/* interrupts to enable */
 };
 
 static int ahci_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
@@ -1552,6 +1554,7 @@
 	void __iomem *mmio = ap->host->iomap[AHCI_PCI_BAR];
 	void __iomem *port_mmio = ahci_port_base(ap);
 	u32 tmp;
+	struct ahci_port_priv *pp = ap->private_data;
 
 	/* clear IRQ */
 	tmp = readl(port_mmio + PORT_IRQ_STAT);
@@ -1559,7 +1562,7 @@
 	writel(1 << ap->port_no, mmio + HOST_IRQ_STAT);
 
 	/* turn IRQ back on */
-	writel(DEF_PORT_IRQ, port_mmio + PORT_IRQ_MASK);
+	writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
 }
 
 static void ahci_error_handler(struct ata_port *ap)
@@ -1713,6 +1716,12 @@
 	pp->cmd_tbl = mem;
 	pp->cmd_tbl_dma = mem_dma;
 
+	/*
+ 	 * Save off initial list of interrupts to be enabled.
+ 	 * This could be changed later
+ 	 */
+	pp->intr_mask = DEF_PORT_IRQ;
+
 	ap->private_data = pp;
 
 	/* engage engines, captain */