mac80211: fix configure_filter invocation after stop

Since configure_filter can sleep now, any multicast
configuration needed to be postponed to a work struct.
This, however, lead to a problem that we could queue
the work, stop the device and then afterwards invoke
configure_filter which may lead to driver hangs and is
a bug. To fix this, we can just cancel the filter work
since it's unnecessary to do after stopping the hw.

Since there are various places that call drv_stop, and
two of them do very similar things, the code for them
can be put into a shared function at the same time.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Tested-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 14 insertions, 16 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 455cc7ade9f5..fa930e01295f 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1086,6 +1086,7 @@ void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
 
 /* Suspend/resume and hw reconfiguration */
 int ieee80211_reconfig(struct ieee80211_local *local);
+void ieee80211_stop_device(struct ieee80211_local *local);
 
 #ifdef CONFIG_PM
 int __ieee80211_suspend(struct ieee80211_hw *hw);
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index b161301056df..5940e69fa33c 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -552,11 +552,7 @@ static int ieee80211_stop(struct net_device *dev)
         ieee80211_recalc_ps(local, -1);
 
         if (local->open_count == 0) {
-                drv_stop(local);
-
-                ieee80211_led_radio(local, false);
-
-                flush_workqueue(local->workqueue);
+                ieee80211_stop_device(local);
 
                 tasklet_disable(&local->tx_pending_tasklet);
                 tasklet_disable(&local->tasklet);
diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c
index a5d2f1fb4417..e535f1c988fe 100644
--- a/net/mac80211/pm.c
+++ b/net/mac80211/pm.c
@@ -107,17 +107,8 @@ int __ieee80211_suspend(struct ieee80211_hw *hw)
         }
 
         /* stop hardware - this must stop RX */
-        if (local->open_count) {
-                ieee80211_led_radio(local, false);
-                drv_stop(local);
-        }
-
-        /*
-         * flush again, in case driver queued work -- it
-         * shouldn't be doing (or cancel everything in the
-         * stop callback) that but better safe than sorry.
-         */
-        flush_workqueue(local->workqueue);
+        if (local->open_count)
+                ieee80211_stop_device(local);
 
         local->suspended = true;
         /* need suspended to be visible before quiescing is false */
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 5eb306377c63..dd6564321369 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1007,6 +1007,16 @@ u32 ieee80211_sta_get_rates(struct ieee80211_local *local,
         return supp_rates;
 }
 
+void ieee80211_stop_device(struct ieee80211_local *local)
+{
+        ieee80211_led_radio(local, false);
+
+        cancel_work_sync(&local->reconfig_filter);
+        drv_stop(local);
+
+        flush_workqueue(local->workqueue);
+}
+
 int ieee80211_reconfig(struct ieee80211_local *local)
 {
         struct ieee80211_hw *hw = &local->hw;