net: ipa: don't suspend/resume modem if not up

The modem network device is set up by ipa_modem_start().  But its
TX queue is not actually started and endpoints enabled until it is
opened.

So avoid stopping the modem network device TX queue and disabling
endpoints on suspend or stop unless the netdev is marked UP.  And
skip attempting to resume unless it is UP.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ipa/ipa_modem.c

@@ -178,6 +178,9 @@ void ipa_modem_suspend(struct net_device *netdev)
 	struct ipa_priv *priv = netdev_priv(netdev);
 	struct ipa *ipa = priv->ipa;
 
+	if (!(netdev->flags & IFF_UP))
+		return;
+
 	netif_stop_queue(netdev);
 
 	ipa_endpoint_suspend_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
@@ -194,6 +197,9 @@ void ipa_modem_resume(struct net_device *netdev)
 	struct ipa_priv *priv = netdev_priv(netdev);
 	struct ipa *ipa = priv->ipa;
 
+	if (!(netdev->flags & IFF_UP))
+		return;
+
 	ipa_endpoint_resume_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
 	ipa_endpoint_resume_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
 
@@ -265,8 +271,10 @@ int ipa_modem_stop(struct ipa *ipa)
 	/* Prevent the modem from triggering a call to ipa_setup() */
 	ipa_smp2p_disable(ipa);
 
-	/* Stop the queue and disable the endpoints if it's open */
+	/* Clean up the netdev and endpoints if it was started */
 	if (netdev) {
+		/* If it was opened, stop it first */
+		if (netdev->flags & IFF_UP)
 			(void)ipa_stop(netdev);
 		ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = NULL;
 		ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = NULL;