smsgiucv: guarantee single iucv connect in thaw

If another smsgiucv_app device exists, suspend / resume fails with
iucv path list corruption, because the same iucv_path_connect is
called twice.
The patch introduces a flag to save connect status of the smsgiucv
path to make sure iucv_path_connect in smsg_pm_restore_thaw is
called only once.
Signed-off-by: NUrsula Braun <ursula.braun@de.ibm.com>
Signed-off-by: NFrank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/s390/net/smsgiucv.c

@@ -47,6 +47,7 @@ static struct device *smsg_dev;
 
 static DEFINE_SPINLOCK(smsg_list_lock);
 static LIST_HEAD(smsg_list);
+static int iucv_path_connected;
 
 static int smsg_path_pending(struct iucv_path *, u8 ipvmid[8], u8 ipuser[16]);
 static void smsg_message_pending(struct iucv_path *, struct iucv_message *);
@@ -142,8 +143,10 @@ static int smsg_pm_freeze(struct device *dev)
 #ifdef CONFIG_PM_DEBUG
 	printk(KERN_WARNING "smsg_pm_freeze\n");
 #endif
-	if (smsg_path)
+	if (smsg_path && iucv_path_connected) {
 		iucv_path_sever(smsg_path, NULL);
+		iucv_path_connected = 0;
+	}
 	return 0;
 }
 
@@ -154,7 +157,7 @@ static int smsg_pm_restore_thaw(struct device *dev)
 #ifdef CONFIG_PM_DEBUG
 	printk(KERN_WARNING "smsg_pm_restore_thaw\n");
 #endif
-	if (smsg_path) {
+	if (smsg_path && iucv_path_connected) {
 		memset(smsg_path, 0, sizeof(*smsg_path));
 		smsg_path->msglim = 255;
 		smsg_path->flags = 0;
@@ -165,6 +168,8 @@ static int smsg_pm_restore_thaw(struct device *dev)
 			printk(KERN_ERR
 			       "iucv_path_connect returned with rc %i\n", rc);
 #endif
+		if (!rc)
+			iucv_path_connected = 1;
 		cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 	}
 	return 0;
@@ -214,6 +219,8 @@ static int __init smsg_init(void)
 			       NULL, NULL, NULL);
 	if (rc)
 		goto out_free_path;
+	else
+		iucv_path_connected = 1;
 	smsg_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 	if (!smsg_dev) {
 		rc = -ENOMEM;