diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 061817a..5e6468a 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1777,7 +1777,7 @@
 	struct ahci_host_priv *hpriv;
 	unsigned int i, handled = 0;
 	void __iomem *mmio;
-	u32 irq_stat;
+	u32 irq_stat, irq_masked;
 
 	VPRINTK("ENTER\n");
 
@@ -1786,16 +1786,17 @@
 
 	/* sigh.  0xffffffff is a valid return from h/w */
 	irq_stat = readl(mmio + HOST_IRQ_STAT);
-	irq_stat &= hpriv->port_map;
 	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;
 
-		if (!(irq_stat & (1 << i)))
+		if (!(irq_masked & (1 << i)))
 			continue;
 
 		ap = host->ports[i];
@@ -1812,6 +1813,15 @@
 		handled = 1;
 	}
 
+	/* 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
+	 * valid one.  Please read section 10.6.2 of ahci 1.1 for more
+	 * information.
+	 *
+	 * Also, use the unmasked value to clear interrupt as spurious
+	 * pending event on a dummy port might cause screaming IRQ.
+	 */
 	writel(irq_stat, mmio + HOST_IRQ_STAT);
 
 	spin_unlock(&host->lock);
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index a37a503..c94e58b 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -729,7 +729,11 @@
 	} else {
 		*policy = pol == &default_policy ? MPOL_DEFAULT :
 						pol->mode;
-		*policy |= pol->flags;
+		/*
+		 * Internal mempolicy flags must be masked off before exposing
+		 * the policy to userspace.
+		 */
+		*policy |= (pol->flags & MPOL_MODE_FLAGS);
 	}
 
 	if (vma) {