nl80211: allow enabling WoWLAN without triggers

It may be desirable to use WoWLAN without triggers to
keep the connection alive to the AP while suspended.
Allow this use by enabling WoWLAN without triggers if
no triggers were requested.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 6472c7f..079fc49 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -6466,8 +6466,8 @@
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
 	struct nlattr *tb[NUM_NL80211_WOWLAN_TRIG];
-	struct cfg80211_wowlan no_triggers = {};
 	struct cfg80211_wowlan new_triggers = {};
+	struct cfg80211_wowlan *ntrig;
 	struct wiphy_wowlan_support *wowlan = &rdev->wiphy.wowlan;
 	int err, i;
 	bool prev_enabled = rdev->wowlan;
@@ -6475,8 +6475,11 @@
 	if (!rdev->wiphy.wowlan.flags && !rdev->wiphy.wowlan.n_patterns)
 		return -EOPNOTSUPP;
 
-	if (!info->attrs[NL80211_ATTR_WOWLAN_TRIGGERS])
-		goto no_triggers;
+	if (!info->attrs[NL80211_ATTR_WOWLAN_TRIGGERS]) {
+		cfg80211_rdev_free_wowlan(rdev);
+		rdev->wowlan = NULL;
+		goto set_wakeup;
+	}
 
 	err = nla_parse(tb, MAX_NL80211_WOWLAN_TRIG,
 			nla_data(info->attrs[NL80211_ATTR_WOWLAN_TRIGGERS]),
@@ -6587,22 +6590,15 @@
 		}
 	}
 
-	if (memcmp(&new_triggers, &no_triggers, sizeof(new_triggers))) {
-		struct cfg80211_wowlan *ntrig;
-		ntrig = kmemdup(&new_triggers, sizeof(new_triggers),
-				GFP_KERNEL);
-		if (!ntrig) {
-			err = -ENOMEM;
-			goto error;
-		}
-		cfg80211_rdev_free_wowlan(rdev);
-		rdev->wowlan = ntrig;
-	} else {
- no_triggers:
-		cfg80211_rdev_free_wowlan(rdev);
-		rdev->wowlan = NULL;
+	ntrig = kmemdup(&new_triggers, sizeof(new_triggers), GFP_KERNEL);
+	if (!ntrig) {
+		err = -ENOMEM;
+		goto error;
 	}
+	cfg80211_rdev_free_wowlan(rdev);
+	rdev->wowlan = ntrig;
 
+ set_wakeup:
 	if (rdev->ops->set_wakeup && prev_enabled != !!rdev->wowlan)
 		rdev->ops->set_wakeup(&rdev->wiphy, rdev->wowlan);