From: Stefano Stabellini <sstabellini@xxxxxxxxxx> [ Upstream commit d90a1ca60a1eccb4383fe203c76223ab4c0799ed ] 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@xxxxxxxxxx> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/xen/pvcalls-front.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c index 3a144eecb6a72..d7438fdc57061 100644 --- a/drivers/xen/pvcalls-front.c +++ b/drivers/xen/pvcalls-front.c @@ -504,8 +504,10 @@ 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; -- 2.20.1
