i40evf: check rings before freeing resources

If the driver gets unloaded during reset recovery, it's possible
that it will attempt to free resources when they're already free.

Add a check to make sure that the Tx and Rx rings actually exist
before dereferencing them to free resources.

Change-ID: I4d2b7e9ede49f634d421a4c5deaa5446bc755eee
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_main.c b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
index b4c632f..98091b4 100644 (file)
--- a/drivers/net/ethernet/intel/i40evf/i40evf_main.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
@@ -2034,6 +2034,9 @@ void i40evf_free_all_tx_resources(struct i40evf_adapter *adapter)
 {
        int i;
 
+       if (!adapter->tx_rings)
+               return;
+
        for (i = 0; i < adapter->num_active_queues; i++)
                if (adapter->tx_rings[i].desc)
                        i40evf_free_tx_resources(&adapter->tx_rings[i]);
@@ -2102,6 +2105,9 @@ void i40evf_free_all_rx_resources(struct i40evf_adapter *adapter)
 {
        int i;
 
+       if (!adapter->rx_rings)
+               return;
+
        for (i = 0; i < adapter->num_active_queues; i++)
                if (adapter->rx_rings[i].desc)
                        i40evf_free_rx_resources(&adapter->rx_rings[i]);