mac80211: unset SDATA_STATE_OFFCHANNEL when cancelling a scan

For client STA interfaces, ieee80211_do_stop unsets the relevant
interface's SDATA_STATE_RUNNING state bit prior to cancelling an
interrupted scan.  When ieee80211_offchannel_return is invoked as
part of cancelling the scan, it doesn't bother unsetting the
SDATA_STATE_OFFCHANNEL bit because it sees that the interface is
down.  Normally this doesn't matter because when the client STA
interface is brought back up, it will probably issue a scan.  But
in some cases (e.g., the user changes the interface type while it
is down), the SDATA_STATE_OFFCHANNEL bit will remain set.  This
prevents the interface queues from being started.  So we
cancel the scan before unsetting the SDATA_STATE_RUNNING bit.
Signed-off-by: Brian Cavagnolo <brian@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/iface.c

@@ -391,6 +391,9 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
 	u32 hw_reconf_flags = 0;
 	int i;
 
+	if (local->scan_sdata == sdata)
+		ieee80211_scan_cancel(local);
+
 	clear_bit(SDATA_STATE_RUNNING, &sdata->state);
 
 	/*
@@ -523,9 +526,6 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
 		synchronize_rcu();
 		skb_queue_purge(&sdata->skb_queue);
 
-		if (local->scan_sdata == sdata)
-			ieee80211_scan_cancel(local);
-
 		/*
 		 * Disable beaconing here for mesh only, AP and IBSS
 		 * are already taken care of.