mac80211: be more careful in suspend/resume

When suspending with all netdevs down, the device
is stopped but we still call a number of driver
callbacks that the driver might not expect. The
same happens during resume, we might call a few
callbacks without starting the driver. Fix this
by checking open_count around more things and
exiting quickly if it is 0.

Also, while at this I noticed that the coverage
class isn't reprogrammed after resume, so add
that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 31 insertions, 26 deletions

diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c
index f87e993e713b..6326d3439861 100644
--- a/net/mac80211/pm.c
+++ b/net/mac80211/pm.c
@@ -34,6 +34,9 @@ int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
         struct ieee80211_sub_if_data *sdata;
         struct sta_info *sta;
 
+        if (!local->open_count)
+                goto suspend;
+
         ieee80211_scan_cancel(local);
 
         if (hw->flags & IEEE80211_HW_AMPDU_AGGREGATION) {
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 5bfb80cba634..8c2df33fd7e8 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1157,27 +1157,37 @@ int ieee80211_reconfig(struct ieee80211_local *local)
         }
 #endif
 
-        /* restart hardware */
-        if (local->open_count) {
-                /*
-                 * Upon resume hardware can sometimes be goofy due to
-                 * various platform / driver / bus issues, so restarting
-                 * the device may at times not work immediately. Propagate
-                 * the error.
-                 */
-                res = drv_start(local);
-                if (res) {
-                        WARN(local->suspended, "Hardware became unavailable "
-                             "upon resume. This could be a software issue "
-                             "prior to suspend or a hardware issue.\n");
-                        return res;
-                }
+        /* setup fragmentation threshold */
+        drv_set_frag_threshold(local, hw->wiphy->frag_threshold);
+
+        /* setup RTS threshold */
+        drv_set_rts_threshold(local, hw->wiphy->rts_threshold);
+
+        /* reset coverage class */
+        drv_set_coverage_class(local, hw->wiphy->coverage_class);
+
+        /* everything else happens only if HW was up & running */
+        if (!local->open_count)
+                goto wake_up;
 
-                ieee80211_led_radio(local, true);
-                ieee80211_mod_tpt_led_trig(local,
-                                           IEEE80211_TPT_LEDTRIG_FL_RADIO, 0);
+        /*
+         * Upon resume hardware can sometimes be goofy due to
+         * various platform / driver / bus issues, so restarting
+         * the device may at times not work immediately. Propagate
+         * the error.
+         */
+        res = drv_start(local);
+        if (res) {
+                WARN(local->suspended, "Hardware became unavailable "
+                     "upon resume. This could be a software issue "
+                     "prior to suspend or a hardware issue.\n");
+                return res;
         }
 
+        ieee80211_led_radio(local, true);
+        ieee80211_mod_tpt_led_trig(local,
+                                   IEEE80211_TPT_LEDTRIG_FL_RADIO, 0);
+
         /* add interfaces */
         list_for_each_entry(sdata, &local->interfaces, list) {
                 if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
@@ -1201,12 +1211,6 @@ int ieee80211_reconfig(struct ieee80211_local *local)
         }
         mutex_unlock(&local->sta_mtx);
 
-        /* setup fragmentation threshold */
-        drv_set_frag_threshold(local, hw->wiphy->frag_threshold);
-
-        /* setup RTS threshold */
-        drv_set_rts_threshold(local, hw->wiphy->rts_threshold);
-
         /* reconfigure hardware */
         ieee80211_hw_config(local, ~0);
 
@@ -1287,9 +1291,7 @@ int ieee80211_reconfig(struct ieee80211_local *local)
                 if (ieee80211_sdata_running(sdata))
                         ieee80211_enable_keys(sdata);
 
-#ifdef CONFIG_PM
  wake_up:
-#endif
         ieee80211_wake_queues_by_reason(hw,
                         IEEE80211_QUEUE_STOP_REASON_SUSPEND);