mac80211: cancel/restart all timers across suspend/resume

We forgot to cancel all timers in mac80211 when suspending.
In particular we forgot to deal with some things that can
cause hardware reconfiguration -- while it is down.

While at it we go ahead and add a warning in ieee80211_sta_work()
if its run while the suspend->resume cycle is in effect. This
should not happen and if it does it would indicate there is
a bug lurking in either mac80211 or mac80211 drivers.

With this now wpa_supplicant doesn't blink when I go to suspend
and resume where as before there where issues with some timers
running during the suspend->resume cycle. This caused a lot of
incorrect assumptions and would at times bring back the device
in an incoherent, but mostly recoverable, state.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 62 insertions, 18 deletions

diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c
index 9d3d89abbb57..7a549f9deb96 100644
--- a/net/mac80211/pm.c
+++ b/net/mac80211/pm.c
@@ -2,6 +2,7 @@
 #include <net/rtnetlink.h>
 
 #include "ieee80211_i.h"
+#include "mesh.h"
 #include "driver-ops.h"
 #include "led.h"
 
@@ -13,11 +14,30 @@ int __ieee80211_suspend(struct ieee80211_hw *hw)
         struct sta_info *sta;
         unsigned long flags;
 
+        ieee80211_scan_cancel(local);
+
         ieee80211_stop_queues_by_reason(hw,
                         IEEE80211_QUEUE_STOP_REASON_SUSPEND);
 
+        /* flush out all packets */
+        synchronize_net();
+
+        local->quiescing = true;
+        /* make quiescing visible to timers everywhere */
+        mb();
+
         flush_workqueue(local->hw.workqueue);
 
+        /* Don't try to run timers while suspended. */
+        del_timer_sync(&local->sta_cleanup);
+
+         /*
+         * Note that this particular timer doesn't need to be
+         * restarted at resume.
+         */
+        cancel_work_sync(&local->dynamic_ps_enable_work);
+        del_timer_sync(&local->dynamic_ps_timer);
+
         /* disable keys */
         list_for_each_entry(sdata, &local->interfaces, list)
                 ieee80211_disable_keys(sdata);
@@ -35,10 +55,20 @@ int __ieee80211_suspend(struct ieee80211_hw *hw)
 
         rcu_read_unlock();
 
+        /* flush again, in case driver queued work */
+        flush_workqueue(local->hw.workqueue);
+
+        /* stop hardware - this must stop RX */
+        if (local->open_count) {
+                ieee80211_led_radio(local, false);
+                drv_stop(local);
+        }
+
         /* remove STAs */
-        if (local->ops->sta_notify) {
-                spin_lock_irqsave(&local->sta_lock, flags);
-                list_for_each_entry(sta, &local->sta_list, list) {
+        spin_lock_irqsave(&local->sta_lock, flags);
+        list_for_each_entry(sta, &local->sta_list, list) {
+                if (local->ops->sta_notify) {
+                        sdata = sta->sdata;
                         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
                                 sdata = container_of(sdata->bss,
                                              struct ieee80211_sub_if_data,
@@ -47,29 +77,43 @@ int __ieee80211_suspend(struct ieee80211_hw *hw)
                         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_REMOVE,
                                        &sta->sta);
                 }
-                spin_unlock_irqrestore(&local->sta_lock, flags);
+
+                mesh_plink_quiesce(sta);
         }
+        spin_unlock_irqrestore(&local->sta_lock, flags);
 
         /* remove all interfaces */
         list_for_each_entry(sdata, &local->interfaces, list) {
-                if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
-                    sdata->vif.type != NL80211_IFTYPE_MONITOR &&
-                    netif_running(sdata->dev)) {
-                        conf.vif = &sdata->vif;
-                        conf.type = sdata->vif.type;
-                        conf.mac_addr = sdata->dev->dev_addr;
-                        drv_remove_interface(local, &conf);
+                switch(sdata->vif.type) {
+                case NL80211_IFTYPE_STATION:
+                        ieee80211_sta_quiesce(sdata);
+                        break;
+                case NL80211_IFTYPE_ADHOC:
+                        ieee80211_ibss_quiesce(sdata);
+                        break;
+                case NL80211_IFTYPE_MESH_POINT:
+                        ieee80211_mesh_quiesce(sdata);
+                        break;
+                case NL80211_IFTYPE_AP_VLAN:
+                case NL80211_IFTYPE_MONITOR:
+                        /* don't tell driver about this */
+                        continue;
+                default:
+                        break;
                 }
-        }
 
-        /* flush again, in case driver queued work */
-        flush_workqueue(local->hw.workqueue);
+                if (!netif_running(sdata->dev))
+                        continue;
 
-        /* stop hardware */
-        if (local->open_count) {
-                ieee80211_led_radio(local, false);
-                drv_stop(local);
+                conf.vif = &sdata->vif;
+                conf.type = sdata->vif.type;
+                conf.mac_addr = sdata->dev->dev_addr;
+                drv_remove_interface(local, &conf);
         }
+
+        local->suspended = true;
+        local->quiescing = false;
+
         return 0;
 }