From 4ae9b105430a56f739764bdaefb90f256e1a25c4 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sat, 5 Jul 2008 13:06:19 -0700
Subject: [PATCH] --- yaml --- r: 98732 b: refs/heads/master c:
 fbe0825752dc34b505777fd59cde4a6ce832eb16 h: refs/heads/master v: v3

---
 [refs]                   |  2 +-
 trunk/drivers/ata/ahci.c | 16 +++++++++++++---
 trunk/mm/mempolicy.c     |  6 +++++-
 3 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index 0136f09bd9a9..9a1ae072f4c2 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 2b54ed9467697b0ce2d60d89e5e4253c9e322c26
+refs/heads/master: fbe0825752dc34b505777fd59cde4a6ce832eb16
diff --git a/trunk/drivers/ata/ahci.c b/trunk/drivers/ata/ahci.c
index 061817a3a0e5..5e6468a7ca4b 100644
--- a/trunk/drivers/ata/ahci.c
+++ b/trunk/drivers/ata/ahci.c
@@ -1777,7 +1777,7 @@ static irqreturn_t ahci_interrupt(int irq, void *dev_instance)
 	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 @@ static irqreturn_t ahci_interrupt(int irq, void *dev_instance)
 
 	/* 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 @@ static irqreturn_t ahci_interrupt(int irq, void *dev_instance)
 		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/trunk/mm/mempolicy.c b/trunk/mm/mempolicy.c
index a37a5034f63d..c94e58b192c3 100644
--- a/trunk/mm/mempolicy.c
+++ b/trunk/mm/mempolicy.c
@@ -729,7 +729,11 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
 	} 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) {