mac80211: perform scan cancel in hw reset work
Move ieee80211_scan_cancel() and all other related code to
ieee80211_restart_work() as ieee80211_restart_hw() is intended to be
callable from any context.
Fix a bug that RTNL lock is not taken during ieee80211_cancel_scan().
Take local->mtx before WARN(test_bit(SCAN_HW_SCANNING, &local->scanning)
to prevent the race condition with __ieee80211_start_scan() described
here: http://marc.info/?l=linux-wireless&m=128516716810537&w=2
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index e24fa5b..494dba1 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -295,7 +295,17 @@
struct ieee80211_local *local =
container_of(work, struct ieee80211_local, restart_work);
+ /* wait for scan work complete */
+ flush_workqueue(local->workqueue);
+
+ mutex_lock(&local->mtx);
+ WARN(test_bit(SCAN_HW_SCANNING, &local->scanning),
+ "%s called with hardware scan in progress\n", __func__);
+ mutex_unlock(&local->mtx);
+
rtnl_lock();
+ if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning)))
+ ieee80211_scan_cancel(local);
ieee80211_reconfig(local);
rtnl_unlock();
}
@@ -306,15 +316,6 @@
trace_api_restart_hw(local);
- /* wait for scan work complete */
- flush_workqueue(local->workqueue);
-
- WARN(test_bit(SCAN_HW_SCANNING, &local->scanning),
- "%s called with hardware scan in progress\n", __func__);
-
- if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning)))
- ieee80211_scan_cancel(local);
-
/* use this reason, ieee80211_reconfig will unblock it */
ieee80211_stop_queues_by_reason(hw,
IEEE80211_QUEUE_STOP_REASON_SUSPEND);