[PATCH net] ibmvnic: Fix partial success login retries

[PATCH net] ibmvnic: Fix partial success login retries

[Thomas Falcon]

In its current state, the driver will handle backing device
login in a loop for a certain number of retries while the
device returns a partial success, indicating that the driver
may need to try again using a smaller number of resources.

The variable it checks to continue retrying may change
over the course of operations, resulting in reallocation
of resources but exits without sending the login attempt.
Guard against this by introducing a boolean variable that
will retain the state indicating that the driver needs to
reattempt login with backing device firmware.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 4bb4646..4382bff 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -796,9 +796,11 @@ static int ibmvnic_login(struct net_device *netdev)
 	struct ibmvnic_adapter *adapter = netdev_priv(netdev);
 	unsigned long timeout = msecs_to_jiffies(30000);
 	int retry_count = 0;
+	bool retry;
 	int rc;
 
 	do {
+		retry = false;
 		if (retry_count > IBMVNIC_MAX_QUEUES) {
 			netdev_warn(netdev, "Login attempts exceeded\n");
 			return -1;
@@ -822,6 +824,9 @@ static int ibmvnic_login(struct net_device *netdev)
 			retry_count++;
 			release_sub_crqs(adapter, 1);
 
+			retry = true;
+			netdev_dbg(netdev,
+				   "Received partial success, retrying...\n");
 			adapter->init_done_rc = 0;
 			reinit_completion(&adapter->init_done);
 			send_cap_queries(adapter);
@@ -849,7 +854,7 @@ static int ibmvnic_login(struct net_device *netdev)
 			netdev_warn(netdev, "Adapter login failed\n");
 			return -1;
 		}
-	} while (adapter->init_done_rc == PARTIALSUCCESS);
+	} while (retry);
 
 	/* handle pending MAC address changes after successful login */
 	if (adapter->mac_change_pending) {
-- 
1.8.3.1

Re: [PATCH net] ibmvnic: Fix partial success login retries

[David Miller]

From: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Date: Thu, 24 May 2018 14:37:53 -0500

> In its current state, the driver will handle backing device
> login in a loop for a certain number of retries while the
> device returns a partial success, indicating that the driver
> may need to try again using a smaller number of resources.
> 
> The variable it checks to continue retrying may change
> over the course of operations, resulting in reallocation
> of resources but exits without sending the login attempt.
> Guard against this by introducing a boolean variable that
> will retain the state indicating that the driver needs to
> reattempt login with backing device firmware.
> 
> Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>

Applied.