From ee1e4f6c4524b5693dcc6e84cfa8c1da6f4fc51c Mon Sep 17 00:00:00 2001
From: John Allen <jallen@linux.vnet.ibm.com>
Date: Mon, 22 Jan 2018 15:43:31 +0100
Subject: [PATCH] ibmvnic: Allocate and request vpd in init_resources

References: bsc#1076872
Patch-mainline: v4.15
Git-commit: 69d08dcbbe34347cbc044629cf6f25d062593dfe

If we request an unsupported mtu value, the vnic server will suggest a
different value. Currently we take the suggested value without question
and login with that value. However, the behavior doesn't seem completely
sane as attempting to change the mtu to some specific value will change
the mtu to some completely different value most of the time. This patch
fixes the issue by logging in with the previously used mtu value and
printing an error message saying that the given mtu is unsupported.

Signed-off-by: John Allen <jallen@linux.vnet.ibm.com>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 1bd3a5edc982..431bcea4f837 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -3625,7 +3625,17 @@ static void handle_request_cap_rsp(union ibmvnic_crq *crq,
 			 *req_value,
 			 (long int)be64_to_cpu(crq->request_capability_rsp.
 					       number), name);
-		*req_value = be64_to_cpu(crq->request_capability_rsp.number);
+
+		if (be16_to_cpu(crq->request_capability_rsp.capability) ==
+		    REQ_MTU) {
+			pr_err("mtu of %llu is not supported. Reverting.\n",
+			       *req_value);
+			*req_value = adapter->fallback.mtu;
+		} else {
+			*req_value =
+				be64_to_cpu(crq->request_capability_rsp.number);
+		}
+
 		ibmvnic_send_req_caps(adapter, 1);
 		return;
 	default:
-- 
2.13.6