[PATCH AUTOSEL for 4.15 175/189] ibmvnic: Reset long term map ID counter

[Sasha Levin]

From: Thomas Falcon <tlfalcon@xxxxxxxxxxxxxxxxxx>

[ Upstream 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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 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 4ba49a98c689..297007678584 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1634,6 +1634,7 @@ 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);
-- 
2.15.1