[PATCH] s390: set online race in the lcs driver

[patch 3/10] s390: set online race in the lcs driver.

From: Michael Holzheu <holzheu@de.ibm.com>

There is a race between lcs_stopcard() and lcs_open_device() which
can lead to the error 'lcs: Error in starting channel, rc=-16'.
lcs_open_device() is invoked when 'ifconfig up' is called due to a
hotplug event, which is caused by register_netdev(). In parallel
lcs_stopcard() is executed. Both functions are sending lcs commands.
The second invocation fails with -EBUSY (-16) as return value.
Move invocation of register_netdev() after invocation of lcs_stopcard
to avoid the race.

Signed-off-by: Frank Pavlic <pavlic@de.ibm.com>

diff --git a/drivers/s390/net/lcs.c b/drivers/s390/net/lcs.c
index 8d0262e..cccfed2 100644 (file)
--- a/drivers/s390/net/lcs.c
+++ b/drivers/s390/net/lcs.c
@@ -11,7 +11,7 @@
  *                       Frank Pavlic (pavlic@de.ibm.com) and
  *                       Martin Schwidefsky <schwidefsky@de.ibm.com>
  *
- *    $Revision: 1.97 $         $Date: 2005/03/31 09:42:02 $
+ *    $Revision: 1.98 $         $Date: 2005/04/18 13:41:29 $
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -59,7 +59,7 @@
 /**
  * initialization string for output
  */
-#define VERSION_LCS_C  "$Revision: 1.97 $"
+#define VERSION_LCS_C  "$Revision: 1.98 $"
 
 static char version[] __initdata = "LCS driver ("VERSION_LCS_C "/" VERSION_LCS_H ")";
 static char debug_buffer[255];
@@ -1098,14 +1098,6 @@ lcs_check_multicast_support(struct lcs_card *card)
                PRINT_ERR("Query IPAssist failed. Assuming unsupported!\n");
                return -EOPNOTSUPP;
        }
-       /* Print out supported assists: IPv6 */
-       PRINT_INFO("LCS device %s %s IPv6 support\n", card->dev->name,
-                  (card->ip_assists_supported & LCS_IPASS_IPV6_SUPPORT) ?
-                  "with" : "without");
-       /* Print out supported assist: Multicast */
-       PRINT_INFO("LCS device %s %s Multicast support\n", card->dev->name,
-                  (card->ip_assists_supported & LCS_IPASS_MULTICAST_SUPPORT) ?
-                  "with" : "without");
        if (card->ip_assists_supported & LCS_IPASS_MULTICAST_SUPPORT)
                return 0;
        return -EOPNOTSUPP;
@@ -2198,30 +2190,39 @@ lcs_new_device(struct ccwgroup_device *ccwgdev)
        if (!dev)
                goto out;
        card->dev = dev;
-netdev_out:
        card->dev->priv = card;
        card->dev->open = lcs_open_device;
        card->dev->stop = lcs_stop_device;
        card->dev->hard_start_xmit = lcs_start_xmit;
        card->dev->get_stats = lcs_getstats;
        SET_MODULE_OWNER(dev);
-       if (lcs_register_netdev(ccwgdev) != 0)
-               goto out;
        memcpy(card->dev->dev_addr, card->mac, LCS_MAC_LENGTH);
 #ifdef CONFIG_IP_MULTICAST
        if (!lcs_check_multicast_support(card))
                card->dev->set_multicast_list = lcs_set_multicast_list;
 #endif
-       netif_stop_queue(card->dev);
+netdev_out:
        lcs_set_allowed_threads(card,0xffffffff);
        if (recover_state == DEV_STATE_RECOVER) {
                lcs_set_multicast_list(card->dev);
                card->dev->flags |= IFF_UP;
                netif_wake_queue(card->dev);
                card->state = DEV_STATE_UP;
-       } else
+       } else {
                lcs_stopcard(card);
+       }
 
+       if (lcs_register_netdev(ccwgdev) != 0)
+               goto out;
+
+       /* Print out supported assists: IPv6 */
+       PRINT_INFO("LCS device %s %s IPv6 support\n", card->dev->name,
+                  (card->ip_assists_supported & LCS_IPASS_IPV6_SUPPORT) ?
+                  "with" : "without");
+       /* Print out supported assist: Multicast */
+       PRINT_INFO("LCS device %s %s Multicast support\n", card->dev->name,
+                  (card->ip_assists_supported & LCS_IPASS_MULTICAST_SUPPORT) ?
+                  "with" : "without");
        return 0;
 out: