From: Selvin Xavier <selvin.xavier@broadcom.com>
Date: Wed, 23 Aug 2017 01:08:07 -0700
Subject: IB: Avoid ib_modify_port() failure for RoCE devices
Patch-mainline: v4.14-rc1
Git-commit: 61e0962d52216f2e5bab59bb055f1210e41f484f
References: bsc#1046306 FATE#322942

IB CM calls ib_modify_port() irrespective of link layer. If the
failure is returned, the mad agent gets unregistered for those
devices. Recently, modify_port() hook was removed from some of the
low level drivers as it was always returning success. This breaks
rdma connection establishment over those devices.
For ethernet devices, Qkey violation and port capabilities are not
applicable. So returning success for RoCE when modify_port hook is
is not implemented.

Cc: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/core/device.c |   11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -1005,14 +1005,17 @@ int ib_modify_port(struct ib_device *dev
 		   u8 port_num, int port_modify_mask,
 		   struct ib_port_modify *port_modify)
 {
-	if (!device->modify_port)
-		return -ENOSYS;
+	int rc;
 
 	if (!rdma_is_port_valid(device, port_num))
 		return -EINVAL;
 
-	return device->modify_port(device, port_num, port_modify_mask,
-				   port_modify);
+	if (device->modify_port)
+		rc = device->modify_port(device, port_num, port_modify_mask,
+					   port_modify);
+	else
+		rc = rdma_protocol_roce(device, port_num) ? 0 : -ENOSYS;
+	return rc;
 }
 EXPORT_SYMBOL(ib_modify_port);