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>

4 files changed, 45 insertions, 0 deletions

diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
index a95affc94629..07656d830bc4 100644
--- a/net/mac80211/agg-rx.c
+++ b/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 */
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index 1df116d4d6e7..e5776ef1717a 100644
--- a/net/mac80211/agg-tx.c
+++ b/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;
diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c
index ef7be1ce2c87..1e6152ac6778 100644
--- a/net/mac80211/pm.c
+++ b/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))
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 1f45573c580c..5b223b216e5a 100644
--- a/net/mac80211/sta_info.h
+++ b/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