mac80211: fix do_stop handling while suspended

When a device is unplugged while suspended, mac80211 is
de-initialized and all interfaces are removed while no
state is actually present in the driver. This can cause
warnings and driver confusion.

Fix this by reordering the do_stop code to not call the
driver when it is suspended, i.e. when there's no state
in the driver anyway.

The previous patches removed a few corner cases in ROC
and virtual monitor interfaces so that now this is safe
to do and no state should be left over.

Reported-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index d0d5f20..8c94195 100644 (file)
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -739,8 +739,6 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
                                 sdata->dev->addr_len);
                spin_unlock_bh(&local->filter_lock);
                netif_addr_unlock_bh(sdata->dev);
-
-               ieee80211_configure_filter(local);
        }
 
        del_timer_sync(&local->dynamic_ps_timer);
@@ -751,6 +749,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
        cancel_delayed_work_sync(&sdata->dfs_cac_timer_work);
 
        if (sdata->wdev.cac_started) {
+               WARN_ON(local->suspended);
                mutex_lock(&local->iflist_mtx);
                ieee80211_vif_release_channel(sdata);
                mutex_unlock(&local->iflist_mtx);
@@ -801,14 +800,9 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
                if (local->monitors == 0) {
                        local->hw.conf.flags &= ~IEEE80211_CONF_MONITOR;
                        hw_reconf_flags |= IEEE80211_CONF_CHANGE_MONITOR;
-                       ieee80211_del_virtual_monitor(local);
                }
 
                ieee80211_adjust_monitor_flags(sdata, -1);
-               ieee80211_configure_filter(local);
-               mutex_lock(&local->mtx);
-               ieee80211_recalc_idle(local);
-               mutex_unlock(&local->mtx);
                break;
        case NL80211_IFTYPE_P2P_DEVICE:
                /* relies on synchronize_rcu() below */
@@ -838,27 +832,10 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
                /* fall through */
        case NL80211_IFTYPE_AP:
                skb_queue_purge(&sdata->skb_queue);
-
-               if (going_down)
-                       drv_remove_interface(local, sdata);
        }
 
        sdata->bss = NULL;
 
-       ieee80211_recalc_ps(local, -1);
-
-       if (local->open_count == 0) {
-               ieee80211_clear_tx_pending(local);
-               ieee80211_stop_device(local);
-
-               /* no reconfiguring after stop! */
-               hw_reconf_flags = 0;
-       }
-
-       /* do after stop to avoid reconfiguring when we stop anyway */
-       if (hw_reconf_flags)
-               ieee80211_hw_config(local, hw_reconf_flags);
-
        spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
        for (i = 0; i < IEEE80211_MAX_QUEUES; i++) {
                skb_queue_walk_safe(&local->pending[i], skb, tmp) {
@@ -871,7 +848,54 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
        }
        spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 
-       if (local->monitors == local->open_count && local->monitors > 0)
+       if (local->open_count == 0)
+               ieee80211_clear_tx_pending(local);
+
+       /*
+        * If the interface goes down while suspended, presumably because
+        * the device was unplugged and that happens before our resume,
+        * then the driver is already unconfigured and the remainder of
+        * this function isn't needed.
+        * XXX: what about WoWLAN? If the device has software state, e.g.
+        *      memory allocated, it might expect teardown commands from
+        *      mac80211 here?
+        */
+       if (local->suspended) {
+               WARN_ON(local->wowlan);
+               WARN_ON(rtnl_dereference(local->monitor_sdata));
+               return;
+       }
+
+       switch (sdata->vif.type) {
+       case NL80211_IFTYPE_AP_VLAN:
+               break;
+       case NL80211_IFTYPE_MONITOR:
+               if (local->monitors == 0)
+                       ieee80211_del_virtual_monitor(local);
+
+               mutex_lock(&local->mtx);
+               ieee80211_recalc_idle(local);
+               mutex_unlock(&local->mtx);
+               break;
+       default:
+               if (going_down)
+                       drv_remove_interface(local, sdata);
+       }
+
+       ieee80211_recalc_ps(local, -1);
+
+       if (local->open_count == 0) {
+               ieee80211_stop_device(local);
+
+               /* no reconfiguring after stop! */
+               return;
+       }
+
+       /* do after stop to avoid reconfiguring when we stop anyway */
+       ieee80211_configure_filter(local);
+       ieee80211_hw_config(local, hw_reconf_flags);
+
+       if (local->monitors == local->open_count)
                ieee80211_add_virtual_monitor(local);
 }