From d944c3d60ac9ec6968d97ac5704155d0afac5216 Mon Sep 17 00:00:00 2001
From: John Allen <jallen@linux.vnet.ibm.com>
Date: Fri, 26 May 2017 10:30:13 -0400
Subject: [PATCH] ibmvnic: Track state of adapter napis

References: fate#322021, bsc#1040855
Patch-mainline: v4.13-rc1
Git-commit: d944c3d60ac9ec6968d97ac5704155d0afac5216

Track the state of ibmvnic napis. The driver can get into states where it
can be reset when napis are already disabled and attempting to disable them
again will cause the driver to hang.

Signed-off-by: John Allen <jallen@linux.vnet.ibm.com>
Signed-off-by: Nathan Fontenot <nfont@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 | 37 ++++++++++++++++++++++++++++---------
 drivers/net/ethernet/ibm/ibmvnic.h |  1 +
 2 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 27f79339e9a8..4997de425b5c 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -518,6 +518,32 @@ static void release_error_buffers(struct ibmvnic_adapter *adapter)
 	spin_unlock_irqrestore(&adapter->error_list_lock, flags);
 }
 
+static void ibmvnic_napi_enable(struct ibmvnic_adapter *adapter)
+{
+	int i;
+
+	if (adapter->napi_enabled)
+		return;
+
+	for (i = 0; i < adapter->req_rx_queues; i++)
+		napi_enable(&adapter->napi[i]);
+
+	adapter->napi_enabled = true;
+}
+
+static void ibmvnic_napi_disable(struct ibmvnic_adapter *adapter)
+{
+	int i;
+
+	if (!adapter->napi_enabled)
+		return;
+
+	for (i = 0; i < adapter->req_rx_queues; i++)
+		napi_disable(&adapter->napi[i]);
+
+	adapter->napi_enabled = false;
+}
+
 static int ibmvnic_login(struct net_device *netdev)
 {
 	struct ibmvnic_adapter *adapter = netdev_priv(netdev);
@@ -674,9 +700,7 @@ static int __ibmvnic_open(struct net_device *netdev)
 
 	adapter->state = VNIC_OPENING;
 	replenish_pools(adapter);
-
-	for (i = 0; i < adapter->req_rx_queues; i++)
-		napi_enable(&adapter->napi[i]);
+	ibmvnic_napi_enable(adapter);
 
 	/* We're ready to receive frames, enable the sub-crq interrupts and
 	 * set the logical link state to up
@@ -779,12 +803,7 @@ static int __ibmvnic_close(struct net_device *netdev)
 
 	adapter->state = VNIC_CLOSING;
 	netif_tx_stop_all_queues(netdev);
-
-	if (adapter->napi) {
-		for (i = 0; i < adapter->req_rx_queues; i++)
-			napi_disable(&adapter->napi[i]);
-	}
-
+	ibmvnic_napi_disable(adapter);
 	clean_tx_pools(adapter);
 
 	if (adapter->tx_scrq) {
diff --git a/drivers/net/ethernet/ibm/ibmvnic.h b/drivers/net/ethernet/ibm/ibmvnic.h
index 4702b48cfa44..4816e0425025 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.h
+++ b/drivers/net/ethernet/ibm/ibmvnic.h
@@ -1031,4 +1031,5 @@ struct ibmvnic_adapter {
 	struct list_head rwi_list;
 	struct work_struct ibmvnic_reset;
 	bool resetting;
+	bool napi_enabled;
 };
-- 
2.10.2