[SRU][linux-lts-vivid][PATCH 2/2][V2] UBUNTU: SAUCE: (no-up) Drivers: hv: vmbus: Fix a bug in hv_need_to_signal_on_read()

[Joseph Salisbury]

From: "K. Y. Srinivasan" <kys at microsoft.com>

BugLink: http://bugs.launchpad.net/bugs/1556264

Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
---
 drivers/hv/ring_buffer.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 70a1a9a..cc0c373 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -103,8 +103,7 @@ static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi)
  *    there is room for the producer to send the pending packet.
  */
 
-static bool hv_need_to_signal_on_read(u32 prev_write_sz,
-				      struct hv_ring_buffer_info *rbi)
+static bool hv_need_to_signal_on_read(struct hv_ring_buffer_info *rbi)
 {
 	u32 cur_write_sz;
 	u32 r_size;
@@ -122,7 +121,7 @@ static bool hv_need_to_signal_on_read(u32 prev_write_sz,
 	cur_write_sz = write_loc >= read_loc ? r_size - (write_loc - read_loc) :
 			read_loc - write_loc;
 
-	if ((prev_write_sz < pending_sz) && (cur_write_sz >= pending_sz))
+	if (cur_write_sz >= pending_sz)
 		return true;
 
 	return false;
@@ -552,7 +551,7 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer,
 
 	spin_unlock_irqrestore(&inring_info->ring_lock, flags);
 
-	*signal = hv_need_to_signal_on_read(bytes_avail_towrite, inring_info);
+	*signal = hv_need_to_signal_on_read(inring_info);
 
 	return 0;
 }
-- 
1.9.1