[PATCH] mac80211: only roll back station states for WDS when suspending

[Luca Coelho <luca@coelho.fi>]

From: Luciano Coelho <luciano.coelho@intel.com>

In normal cases (i.e. when we are fully associated), cfg80211 takes
care of removing all the stations before calling suspend in mac80211.

But in the corner case when we suspend during authentication or
association, mac80211 needs to roll back the station states.  But we
shouldn't roll back the station states in the suspend function,
because this is taken care of in other parts of the code, except for
WDS interfaces.  For AP types of interfaces, cfg80211 takes care of
disconnecting all stations before calling the driver's suspend code.
For station interfaces, this is done in the quiesce code.

For WDS interfaces we still need to do it here, so move the code into
a new switch case for WDS.

Cc: stable@kernel.org [3.15+]
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
---

In v2:

   * Reworked the commit message [Johannes]


 net/mac80211/pm.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c
index 8c8c678..ca405b6 100644
--- a/net/mac80211/pm.c
+++ b/net/mac80211/pm.c
@@ -86,20 +86,6 @@ int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
 		}
 	}
 
-	/* tear down aggregation sessions and remove STAs */
-	mutex_lock(&local->sta_mtx);
-	list_for_each_entry(sta, &local->sta_list, list) {
-		if (sta->uploaded) {
-			enum ieee80211_sta_state state;
-
-			state = sta->sta_state;
-			for (; state > IEEE80211_STA_NOTEXIST; state--)
-				WARN_ON(drv_sta_state(local, sta->sdata, sta,
-						      state, state - 1));
-		}
-	}
-	mutex_unlock(&local->sta_mtx);
-
 	/* remove all interfaces that were created in the driver */
 	list_for_each_entry(sdata, &local->interfaces, list) {
 		if (!ieee80211_sdata_running(sdata))
@@ -111,6 +97,21 @@ int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
 		case NL80211_IFTYPE_STATION:
 			ieee80211_mgd_quiesce(sdata);
 			break;
+		case NL80211_IFTYPE_WDS:
+			/* tear down aggregation sessions and remove STAs */
+			mutex_lock(&local->sta_mtx);
+			sta = sdata->u.wds.sta;
+			if (sta && sta->uploaded) {
+				enum ieee80211_sta_state state;
+
+				state = sta->sta_state;
+				for (; state > IEEE80211_STA_NOTEXIST; state--)
+					WARN_ON(drv_sta_state(local, sta->sdata,
+							      sta, state,
+							      state - 1));
+			}
+			mutex_unlock(&local->sta_mtx);
+			break;
 		default:
 			break;
 		}
-- 
2.1.4