mac80211: Tear down aggregation sessions for suspend/resume

When the driver has been notified with a STA_REMOVE, it tears down
the internal ADDBA state. On resume, trying to initiate aggregation would
fail because mac80211 has not cleared the operational state for that <TID,STA>.
This can be fixed by tearing down the existing sessions on a suspend.

Also, the driver can initiate a new BA session when suspend is in progress.
This is fixed by marking the station as being in suspend state and
denying ADDBA requests for such STAs.
Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/agg-rx.c

@@ -197,6 +197,14 @@ void ieee80211_process_addba_request(struct ieee80211_local *local,
 
 	status = WLAN_STATUS_REQUEST_DECLINED;
 
+	if (test_sta_flags(sta, WLAN_STA_SUSPEND)) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+		printk(KERN_DEBUG "Suspend in progress. "
+		       "Denying ADDBA request\n");
+#endif
+		goto end_no_lock;
+	}
+
 	/* sanity check for incoming parameters:
 	 * check if configuration can support the BA policy
 	 * and if buffer size does not exceeds max value */

net/mac80211/agg-tx.c

@@ -257,6 +257,15 @@ int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 		goto unlock;
 	}
 
+	if (test_sta_flags(sta, WLAN_STA_SUSPEND)) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+		printk(KERN_DEBUG "Suspend in progress. "
+		       "Denying BA session request\n");
+#endif
+		ret = -EINVAL;
+		goto unlock;
+	}
+
 	spin_lock_bh(&sta->lock);
 
 	sdata = sta->sdata;

net/mac80211/pm.c

@@ -21,6 +21,19 @@ int __ieee80211_suspend(struct ieee80211_hw *hw)
 	list_for_each_entry(sdata, &local->interfaces, list)
 		ieee80211_disable_keys(sdata);
 
+	/* Tear down aggregation sessions */
+
+	rcu_read_lock();
+
+	if (hw->flags & IEEE80211_HW_AMPDU_AGGREGATION) {
+		list_for_each_entry_rcu(sta, &local->sta_list, list) {
+			set_sta_flags(sta, WLAN_STA_SUSPEND);
+			ieee80211_sta_tear_down_BA_sessions(sta);
+		}
+	}
+
+	rcu_read_unlock();
+
 	/* remove STAs */
 	if (local->ops->sta_notify) {
 		spin_lock_irqsave(&local->sta_lock, flags);
@@ -102,6 +115,18 @@ int __ieee80211_resume(struct ieee80211_hw *hw)
 		spin_unlock_irqrestore(&local->sta_lock, flags);
 	}
 
+	/* Clear Suspend state so that ADDBA requests can be processed */
+
+	rcu_read_lock();
+
+	if (hw->flags & IEEE80211_HW_AMPDU_AGGREGATION) {
+		list_for_each_entry_rcu(sta, &local->sta_list, list) {
+			clear_sta_flags(sta, WLAN_STA_SUSPEND);
+		}
+	}
+
+	rcu_read_unlock();
+
 	/* add back keys */
 	list_for_each_entry(sdata, &local->interfaces, list)
 		if (netif_running(sdata->dev))

net/mac80211/sta_info.h

@@ -35,6 +35,8 @@
  *	IEEE80211_TX_CTL_CLEAR_PS_FILT control flag) when the next
  *	frame to this station is transmitted.
  * @WLAN_STA_MFP: Management frame protection is used with this STA.
+ * @WLAN_STA_SUSPEND: Set/cleared during a suspend/resume cycle.
+ *	Used to deny ADDBA requests (both TX and RX).
  */
 enum ieee80211_sta_info_flags {
 	WLAN_STA_AUTH		= 1<<0,
@@ -48,6 +50,7 @@ enum ieee80211_sta_info_flags {
 	WLAN_STA_PSPOLL		= 1<<8,
 	WLAN_STA_CLEAR_PS_FILT	= 1<<9,
 	WLAN_STA_MFP		= 1<<10,
+	WLAN_STA_SUSPEND	= 1<<11
 };
 
 #define STA_TID_NUM 16