netdev - [PATCH net] ibmvnic: Wait for device response when changing MAC

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Date:   Mon, 29 Jan 2018 13:45:05 -0600
From:   Thomas Falcon <tlfalcon@...ux.vnet.ibm.com>
To:     netdev@...r.kernel.org
Cc:     nfont@...ux.vnet.ibm.com, jallen@...ux.vnet.ibm.com,
        Thomas Falcon <tlfalcon@...ux.vnet.ibm.com>
Subject: [PATCH net] ibmvnic: Wait for device response when changing MAC

Wait for a response from the VNIC server before exiting after setting
the MAC address. The resolves an issue with bonding a VNIC client in
ALB or TLB modes. The bonding driver was changing the MAC address more
rapidly than the device could respond, causing the following errors.

"bond0: the hw address of slave eth2 is in use by the bond;
couldn't find a slave with a free hw address to give it
(this should not have happened)"

If the function waits until the change is finalized, these errors are
avoided.

Signed-off-by: Thomas Falcon <tlfalcon@...ux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index b65f5f3..d4e8733 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1543,15 +1543,19 @@ static int __ibmvnic_set_mac(struct net_device *netdev, struct sockaddr *p)
 	crq.change_mac_addr.first = IBMVNIC_CRQ_CMD;
 	crq.change_mac_addr.cmd = CHANGE_MAC_ADDR;
 	ether_addr_copy(&crq.change_mac_addr.mac_addr[0], addr->sa_data);
+
+	init_completion(&adapter->fw_done);
 	ibmvnic_send_crq(adapter, &crq);
+	wait_for_completion(&adapter->fw_done);
 	/* netdev->dev_addr is changed in handle_change_mac_rsp function */
-	return 0;
+	return adapter->fw_done_rc ? -EIO : 0;
 }
 
 static int ibmvnic_set_mac(struct net_device *netdev, void *p)
 {
 	struct ibmvnic_adapter *adapter = netdev_priv(netdev);
 	struct sockaddr *addr = p;
+	int rc;
 
 	if (adapter->state == VNIC_PROBED) {
 		memcpy(&adapter->desired.mac, addr, sizeof(struct sockaddr));
@@ -1559,9 +1563,9 @@ static int ibmvnic_set_mac(struct net_device *netdev, void *p)
 		return 0;
 	}
 
-	__ibmvnic_set_mac(netdev, addr);
+	rc = __ibmvnic_set_mac(netdev, addr);
 
-	return 0;
+	return rc;
 }
 
 /**
@@ -3558,8 +3562,8 @@ static void handle_error_indication(union ibmvnic_crq *crq,
 		ibmvnic_reset(adapter, VNIC_RESET_NON_FATAL);
 }
 
-static void handle_change_mac_rsp(union ibmvnic_crq *crq,
-				  struct ibmvnic_adapter *adapter)
+static int handle_change_mac_rsp(union ibmvnic_crq *crq,
+				 struct ibmvnic_adapter *adapter)
 {
 	struct net_device *netdev = adapter->netdev;
 	struct device *dev = &adapter->vdev->dev;
@@ -3568,10 +3572,13 @@ static void handle_change_mac_rsp(union ibmvnic_crq *crq,
 	rc = crq->change_mac_addr_rsp.rc.code;
 	if (rc) {
 		dev_err(dev, "Error %ld in CHANGE_MAC_ADDR_RSP\n", rc);
-		return;
+		goto out;
 	}
 	memcpy(netdev->dev_addr, &crq->change_mac_addr_rsp.mac_addr[0],
 	       ETH_ALEN);
+out:
+	complete(&adapter->fw_done);
+	return rc;
 }
 
 static void handle_request_cap_rsp(union ibmvnic_crq *crq,
@@ -4031,7 +4038,7 @@ static void ibmvnic_handle_crq(union ibmvnic_crq *crq,
 		break;
 	case CHANGE_MAC_ADDR_RSP:
 		netdev_dbg(netdev, "Got MAC address change Response\n");
-		handle_change_mac_rsp(crq, adapter);
+		adapter->fw_done_rc = handle_change_mac_rsp(crq, adapter);
 		break;
 	case ERROR_INDICATION:
 		netdev_dbg(netdev, "Got Error Indication\n");
-- 
2.7.5