cfg80211: accept no-op interface mode changes

When somebody tries to set the interface mode to the existing
mode, don't ask the driver but silently accept the setting.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index b84a9b4fe96a..0fd1db6e95bb 100644
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -66,6 +66,7 @@ int cfg80211_wext_siwmode(struct net_device *dev, struct iw_request_info *info,
         struct cfg80211_registered_device *rdev;
         struct vif_params vifparams;
         enum nl80211_iftype type;
+        int ret;
 
         if (!wdev)
                 return -EOPNOTSUPP;
@@ -96,10 +97,16 @@ int cfg80211_wext_siwmode(struct net_device *dev, struct iw_request_info *info,
                 return -EINVAL;
         }
 
+        if (type == wdev->iftype)
+                return 0;
+
         memset(&vifparams, 0, sizeof(vifparams));
 
-        return rdev->ops->change_virtual_intf(wdev->wiphy, dev->ifindex, type,
-                                              NULL, &vifparams);
+        ret = rdev->ops->change_virtual_intf(wdev->wiphy, dev->ifindex, type,
+                                             NULL, &vifparams);
+        WARN_ON(!ret && wdev->iftype != type);
+
+        return ret;
 }
 EXPORT_SYMBOL(cfg80211_wext_siwmode);