diff --git a/[refs] b/[refs]
index dbd1872f3dea..0d621db9d86b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ef0d5b23022e207e9f367de52f4172daab3ac690
+refs/heads/master: df2a4a711478f5fc28b3ac85f07e191591e31eb0
diff --git a/trunk/drivers/staging/hv/ring_buffer.c b/trunk/drivers/staging/hv/ring_buffer.c
index 932af1a01a1e..8b625533fe43 100644
--- a/trunk/drivers/staging/hv/ring_buffer.c
+++ b/trunk/drivers/staging/hv/ring_buffer.c
@@ -50,6 +50,8 @@ hv_get_ringbuffer_availbytes(struct hv_ring_buffer_info *rbi,
 {
 	u32 read_loc, write_loc;
 
+	smp_read_barrier_depends();
+
 	/* Capture the read/write indices before they changed */
 	read_loc = rbi->ring_buffer->read_index;
 	write_loc = rbi->ring_buffer->write_index;