From: Stefano Stabellini <sstabellini@kernel.org>
Date: Fri, 21 Dec 2018 23:06:32 +0000 (-0800)
Subject: pvcalls-front: don't return error when the ring is full
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=d90a1ca60a1eccb4383fe203c76223ab4c0799ed;p=android-x86%2Fkernel.git

pvcalls-front: don't return error when the ring is full

When the ring is full, size == array_size. It is not an error condition,
so simply return 0 instead of an error.

Signed-off-by: Stefano Stabellini <stefanos@xilinx.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---

diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
index 01588582ae66..1a893a164349 100644
--- a/drivers/xen/pvcalls-front.c
+++ b/drivers/xen/pvcalls-front.c
@@ -475,8 +475,10 @@ static int __write_ring(struct pvcalls_data_intf *intf,
 	virt_mb();
 
 	size = pvcalls_queued(prod, cons, array_size);
-	if (size >= array_size)
+	if (size > array_size)
 		return -EINVAL;
+	if (size == array_size)
+		return 0;
 	if (len > array_size - size)
 		len = array_size - size;