i40evf: request reset on tx hang

If the kernel watchdog bites us, ask the PF to reset us and attempt to
reinit the driver.

Change-ID: Ic97665aeeed71ce712b9c4f057e78ff8372522b9
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/i40evf/i40evf.h

@@ -287,6 +287,7 @@ void i40evf_add_vlans(struct i40evf_adapter *adapter);
 void i40evf_del_vlans(struct i40evf_adapter *adapter);
 void i40evf_set_promiscuous(struct i40evf_adapter *adapter, int flags);
 void i40evf_request_stats(struct i40evf_adapter *adapter);
+void i40evf_request_reset(struct i40evf_adapter *adapter);
 void i40evf_virtchnl_completion(struct i40evf_adapter *adapter,
 				enum i40e_virtchnl_ops v_opcode,
 				i40e_status v_retval, u8 *msg, u16 msglen);

drivers/net/ethernet/intel/i40evf/i40evf_main.c

@@ -167,9 +167,13 @@ static void i40evf_tx_timeout(struct net_device *netdev)
 	struct i40evf_adapter *adapter = netdev_priv(netdev);
 
 	adapter->tx_timeout_count++;
-
-	/* Do the reset outside of interrupt context */
-	schedule_work(&adapter->reset_task);
+	dev_info(&adapter->pdev->dev, "TX timeout detected.\n");
+	if (!(adapter->flags & I40EVF_FLAG_RESET_PENDING)) {
+		dev_info(&adapter->pdev->dev, "Requesting reset from PF\n");
+		i40evf_request_reset(adapter);
+		adapter->flags |= I40EVF_FLAG_RESET_PENDING;
+		schedule_work(&adapter->reset_task);
+	}
 }
 
 /**

drivers/net/ethernet/intel/i40evf/i40evf_virtchnl.c

@@ -654,6 +654,18 @@ void i40evf_request_stats(struct i40evf_adapter *adapter)
 		/* if the request failed, don't lock out others */
 		adapter->current_op = I40E_VIRTCHNL_OP_UNKNOWN;
 }
+/**
+ * i40evf_request_reset
+ * @adapter: adapter structure
+ *
+ * Request that the PF reset this VF. No response is expected.
+ **/
+void i40evf_request_reset(struct i40evf_adapter *adapter)
+{
+	/* Don't check CURRENT_OP - this is always higher priority */
+	i40evf_send_pf_msg(adapter, I40E_VIRTCHNL_OP_RESET_VF, NULL, 0);
+	adapter->current_op = I40E_VIRTCHNL_OP_UNKNOWN;
+}
 
 /**
  * i40evf_virtchnl_completion