From 77bc0cafa1f705c0d10c14c58b1c3fd2c35c74bc Mon Sep 17 00:00:00 2001
From: "K. Y. Srinivasan" <kys@microsoft.com>
Date: Sat, 1 Dec 2012 06:46:55 -0800
Subject: [PATCH] --- yaml --- r: 354998 b: refs/heads/master c:
 5ab05951c586a2ed9e19a3ed8c437346bfabbfb7 h: refs/heads/master v: v3

---
 [refs]                       |  2 +-
 trunk/drivers/hv/vmbus_drv.c | 10 ++++++----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index 599fe0d32f64..73caf0203446 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b0209501dc7586cbfbf6d023f2dd3ce4621aff2c
+refs/heads/master: 5ab05951c586a2ed9e19a3ed8c437346bfabbfb7
diff --git a/trunk/drivers/hv/vmbus_drv.c b/trunk/drivers/hv/vmbus_drv.c
index e066d418be97..797142c07fa0 100644
--- a/trunk/drivers/hv/vmbus_drv.c
+++ b/trunk/drivers/hv/vmbus_drv.c
@@ -454,6 +454,12 @@ static irqreturn_t vmbus_isr(int irq, void *dev_id)
 	union hv_synic_event_flags *event;
 	bool handled = false;
 
+	page_addr = hv_context.synic_event_page[cpu];
+	if (page_addr == NULL)
+		return IRQ_NONE;
+
+	event = (union hv_synic_event_flags *)page_addr +
+					 VMBUS_MESSAGE_SINT;
 	/*
 	 * Check for events before checking for messages. This is the order
 	 * in which events and messages are checked in Windows guests on
@@ -463,10 +469,6 @@ static irqreturn_t vmbus_isr(int irq, void *dev_id)
 	if ((vmbus_proto_version == VERSION_WS2008) ||
 		(vmbus_proto_version == VERSION_WIN7)) {
 
-		page_addr = hv_context.synic_event_page[cpu];
-		event = (union hv_synic_event_flags *)page_addr +
-					 VMBUS_MESSAGE_SINT;
-
 		/* Since we are a child, we only need to check bit 0 */
 		if (sync_test_and_clear_bit(0,
 			(unsigned long *) &event->flags32[0])) {