From faefaa97215a0c05105d7ae180fe1a3b5979ad1f Mon Sep 17 00:00:00 2001
From: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Date: Fri, 9 Feb 2018 11:41:09 -0600
Subject: [PATCH] ibmvnic: Reset long term map ID counter

References: bsc#1080364
Patch-mainline: v4.16-rc1
Git-commit: faefaa97215a0c05105d7ae180fe1a3b5979ad1f

When allocating RX or TX buffer pools, the driver needs to provide a
unique mapping ID to firmware for each pool. This value is assigned
using a counter which is incremented after a new pool is created. The
ID can be an integer ranging from 1-255. When migrating to a device
that requests a different number of queues, this value was not being
reset properly. As a result, after enough migrations, the counter
exceeded the upper bound and pool creation failed. This is fixed by
resetting the counter to one in this case.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index dd4a2946e1da..ce127a72cda2 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1644,6 +1644,7 @@ static int do_reset(struct ibmvnic_adapter *adapter,
 				return rc;
 		} else if (adapter->req_rx_queues != old_num_rx_queues ||
 			   adapter->req_tx_queues != old_num_tx_queues) {
+			adapter->map_id = 1;
 			release_rx_pools(adapter);
 			release_tx_pools(adapter);
 			init_rx_pools(netdev);
-- 
2.13.6