From: Bryan Tan <bryantan@vmware.com>
Date: Wed, 20 Dec 2017 09:50:01 -0800
Subject: RDMA/vmw_pvrdma: Use refcount_dec_and_test to avoid warning
Patch-mainline: v4.15-rc6
Git-commit: 30a366a9dabd05a0d218288b7d732649886b6a53
References: bsc#1046306 FATE#322942

refcount_dec generates a warning when the operation
causes the refcount to hit zero. Avoid this by using
refcount_dec_and_test.

Fixes: 8b10ba783c9d ("RDMA/vmw_pvrdma: Add shared receive queue support")
Reviewed-by: Adit Ranadive <aditr@vmware.com>
Reviewed-by: Aditya Sarwade <asarwade@vmware.com>
Reviewed-by: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: Bryan Tan <bryantan@vmware.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/vmw_pvrdma/pvrdma_srq.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_srq.c
+++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_srq.c
@@ -236,8 +236,8 @@ static void pvrdma_free_srq(struct pvrdm
 	dev->srq_tbl[srq->srq_handle] = NULL;
 	spin_unlock_irqrestore(&dev->srq_tbl_lock, flags);
 
-	refcount_dec(&srq->refcnt);
-	wait_event(srq->wait, !refcount_read(&srq->refcnt));
+	if (!refcount_dec_and_test(&srq->refcnt))
+		wait_event(srq->wait, !refcount_read(&srq->refcnt));
 
 	/* There is no support for kernel clients, so this is safe. */
 	ib_umem_release(srq->umem);